There are essentially four categories of promotion you need to do:
1) Inbound marketing. Have a solid blog and social media plan in place, which doesn't ignore SEO and link building. (My upcoming book for The Pragmatic Bookshelf is exactly for people in your position: http://technicalblogging.com. Sorry for the plug, but hey, we are talking about promotion :)
2) Hustling. Get in touch with as many bloggers and mailing list owners in your niche as possible, offer to guest blog, reach out to journalists with a compelling story, and so on. Do the heavy work so that all they have to do is say YES. This is at the core of hustling.
3) Paid advertising. Online and offline advertisement can be amazing tools to grow your business. You need to be careful though, and optimize your campaigns or it's very easy to bleed money.
4) Affiliates and rewarded referrals. Give an incentive to those who want to promote your app. You can give monetary compensation to your affiliates or provide some perks to your users (e.g., free premium account for you when you refer someone who buys a premium subscription).
I keep reading SEO, SEO, and more SEO. But what does that really entails? As a web developer, I thought that doing nothing (other than providing quality content) and not trying to skew search results is the best path to go?
When we talk about SEO, we are really talking about two different efforts, on-page SEO and off-page SEO.
On-page SEO is all about ensuring that your content can be fairly evaluated by search engines and humans. For example, changing the permalink structure of your posts from /?p=13 to /understanding-dependency-injection is not gaming the system; it's helping Google (and humans) figure out what your content is really about.
Off-page SEO is what you do outside of your pages to help Google and humans discover your content, as well as providing Google with positive indicators of the importance and relevance of your content. This is what most developers object to.
Consider this. If you have a wonderful article on a blog that you never promote and without an existing audience, your chances of being linked to are slim. Google's ranking algorithm will unfairly think that your content is not that great given that nobody is linking to it.
Your off-page SEO efforts are meant to promote your content, getting people to see it, and obtaining backlinks in legitimate ways. Submitting a quality article to HN, for example, provides value to this community and it's good from a SEO standpoint.
Contrary to popular belief, white hat SEO is good for the web and crucial for the promotion of your app or products.
The reason we object to it is that in reality it's spam. 99% of the time it's not a great article, it's crap. You're not writing it out of joy, it's to get links and make a computer deep in google think it's relevant. You need to trick google into thinking people like it so you spam wherever you can and pray you get those links.
There aren't 100 great links per day on HN. It's actually extremely difficult to write good content. Yet there are tens of thousands if not hundreds of thousands of companies doing this.
All off-page SEO is grey as you're essentially trying to trick google into thinking your content is better than organic content. But is there any organic content any more?
On the other hand, we have to get off our high horse. Real life is full of spam, TV adverts, radio adverts, billboards, networking events where you have to filter the schmoozers from the interesting.
The web is the same way and if you don't compete to get your content out there, you competitor will. As everyone does it now, you have to do it too.
So I agree with you, but I'm more realistic about the fact that most content produced is going to suck.
There is at leas one SEO element that you can do without compromising your ethics: Study which the most searched keywords are in your niche, and use those keywords in what you would have published anyway (home page, blog posts, press releases, whatever).
This is not just SEO, it is adopting the language of your users, which is good in itself.
I think it comes down to persistence. The methods you use will vary over time and depending on your app, but the key is to keep trying things and learning from each one.
When I launched Hacker Newsletter (http://www.hackernewsletter.com) I was thinking I would get 1000+ sign-ups the first month. It was more like 100, but what I did do was keep publishing it each week and over time I kept trying things, making connections, and proving it was something serious. Now I'm approaching 6000 subscribers and growing each week.
I've reached the point where I don't distinguish between programming and writing -- to me they are both people being creative and trying to create scalable things people want.
I do a lot of micro-projects. Sometimes the projects are web apps. Sometimes the projects are simply essays. Lately I've been mixing them up some -- so, for instance, something like a social site for people interested in X, with a freemium model for an app that helps a lot with X.
So my advice is to not think of your webapp as simply a hunk of code that you are trying to get out to people. Instead, think of yourself as on a mission to care about/promote/help fix X, then mix and match various formats to reach out to people who might be interested. As part of reaching out and emotionally engaging with people, you'll promote and sell your webapp. My opinion, for what it's worth.
When I launched http://www.scribophile.com/, a site for writers, I made a list of 50 writing blogs. They didn't have to be big names; writers love to write so there's lots of writers' blogs out there. I sent them a friendly and business-speak-free invitation to try the site with a free premium upgrade. Not everyone took me up on it, but a subset of those who did ended up participating and blogging about the site. A few years later and I still get traffic from some of those blog posts. I also still continue reaching out to bloggers, but now offering a month's ad slot if they're interested in writing about us. Now that the site has significant traffic, it's a great incentive for them.
Make sure to reach out to people with a carrot of some sort--give them an extra reason to want to write about you. You'll never get a 100% success rate, but even a 10% success rate will be worth it.
http://SmallPayroll.ca was a one-man-in-his-spare-time project until recently. What I did was:
1. SEM - Google AdWords mostly. I spent a fair time on this, partially because my day job at the time was in the SEM field
2. Organic - I got a great domain that contained my primary keywords, got a landing page built, and it ended up driving a lot of organic traffic. I also set up a blog on the main site. The blog was good for traffic, but not that great for conversions.
3. Referrals - my app is mostly used by people that hire domestic help, so I tried talking to the agencies that help people find that help. Hard to measure that one.
4. Provide awesome customer service - I have been told by several of my customers that they have sent their friends.
5. Free trial - The app gives a 30 day free trial. Many customers have thanked me for that.
Nice work launching this on the side, I know how exhilarating it can feel when people pay you for what you made.
One comment – The orange and brown color combination on your landing page looks visually tiring to me, which was probably why someone else said that your site looks depressing.
Take color psychology into account, here's a link I googled that touches on that:
Have you written about your experiences with transitioning from "spare time project" to what it is now? I saw that there is a blog for smallpayroll.ca, but do you have a personal blog that covers the start of your business and beyond?
I'm very interested in transitioning spare-time projects into something real. Thanks for any info, and congratulations on smallpayroll.ca!
There are some other people involved now, and they've asked that I hold off on anything like that for a little bit. http://ertw.com/blog/ is where it'll be.
I get depressed regarding income taxes, especially for low-income people (i.e., the nannies). Did you know that on a proportional basis, in nearly every country with "progressive" income taxes, the working poor pay the most tithes to the government than they ever have? If you compare the institution of income taxes in "democracies" in the early 20th century to now, the poor have shouldered most of the burden, proportional to income. Kind of flips the whole bleeding heart mechanism for "redistribution of wealth" thing on its head, IMO.
Anyway, I don't want to turn this into a political discussion but that was the reason behind my comment.
I think it's funny that this is so high on the front page, yet there are no comments yet. Seems everyone is hoping to find the magic bullet.
Unfortunately, I don't think there is a one-size-fits all solution. You might cover a college campus in stickers, pair up with a local organization to use you app at a function, visit businesses and pitch it, hound tech bloggers, etc.
Do you have a web app? If you do, this would have been a nice opportunity. Tell us what it is, and ask for advice on how you might promote this specific kind of web app.
Hi. When we first released http://limelightapp.com/ the only thing we did was post it on Hacker News. It made the first page for a few hours. In addition to generating really great feedback from the community, it also generated a decent amount of traffic (about 6000 unique visitors.) Later that day, our app got picked up on http://www.thenextweb.com/ and a few Chinese sites. The article on TNW generated about 200 tweets. Within about a week or two we had enough paid subscribers to cover all our recurring expenses. Everything since then has been profit.
Since then we've started a blog and we've got some of the other promotional ideas in the works as well. But at least initially I think we really benefited not just from the discussion on HN, but the traffic. There is a large overlap between the community here and our product's target audience.
Just FYI, TripLingo has been featured on Mashable, TNW, RWW, etc., and each of those posts generated between 200-1k tweets. Problem is, most of them are just bots that auto-tweet stuff from those sites. Probably got 10-15 legit tweets off of each. But be wary of tweets off of sites like that, I doubt anyone legit follows the people auto-tweeting.
Which isn't to say we didn't see a lot of traffic from those articles, just not from Twitter.
Hopefully you had a pre-launch page where you collected email addresses, then you can email these people upon launch.
Facebook or Google cpc ads.
Submit your site to business/product directories.
Post about your web app on relevant forums (ie. if it is an app to help accountants, find some accountant forums to post on).
Join linkedIn groups and post about your app in there.
Create a facebook page/twitter and post updates regularly. Include these on your webpage, in your email signature and try to get as many likes/followers as you can.
Cold call/Cold email anyone you can find that are potential customers.
If you can find news and other interesting items related to the web app, set up a Twitter, Facebook group, blog, Tumblr, etc. and shovel a couple pieces of content on there a day. Search Twitter and follow everyone talking about that niche, retweet their stuff, do the follow Friday posts, etc. (Take a look at http://challenge.co for more ideas on testing the market first, which you can then use to promote your app.)
Hopefully you had a pre-launch page where you collected email addresses, then you can email these people upon launch.
Typically this is a pre-development page, whereby you're basically tricking people into thinking you already have something, just to gauge the viability of what you're thinking of building.
It doesn't have to be pre-development. For my product, I created this page about 3 months after development began, and 3 months before public release. I used the signups to get beta testers before launch, and then announced to the rest after launch.
Anything can be a sleazy practice if people use it for sleazy purposes, but it's not the practice itself.
I've seen people recommend doing exactly what I described. Obviously, being honest about what's up is not a bad thing, but that's not what I was talking about.
What's wrong with gauging interest? If people are genuinely interested in what you are proposing (whether it is built or not), they are genuinely interested. They will remain genuinely interested when you are eventually done with the product and ready to launch.
If you are solving someone's problem, they will be happy regardless of your development state.
For http://www.hearts-cardgame.com/ I wait until you are into your second game and then I slide down a little, uh, top banner (what are those things called?) which has the text
"Hi there! Looks like you're enjoying the game. That's great! We'd love it if you could help us out by sharing it with your friends:"
And then has the usual facebook/twitter/etc buttons. There is also a discreet "Share with your friends" link that makes the banner pop down, I like that more than having all those ugly buttons visible the whole time. I wait until you're into your second game because I figure by that point you must like the game, otherwise you'd have left, and then it's maybe more likely that you'll help me promote it.
All my online card games (3 of them) also have a "Also try our other games: X and Y" links, which drive a fair bit of traffic between them.
That's interesting. It's similar technique to all those iphone apps/games that ask you to rate them in appstore after playing for a while.
Did you measure the conversion rate of this rollover (that's how I call that stuff on websites)? How many people actually use it among those who seen it? And maybe what percent of people exits your game when you show them the rollover?
A cost effective way of getting users (I'm guessing this is ultimately what you want) at the same time as getting decent feedback is to use a crowdsourcing solution to get educated / computer using people to review your site. Ask them to sign up and use the product and go through a number of steps. Pay a thousand people to do this. If you have a good product they will keep using it.
On average how much would you pay for a person? $5 or $10, what would be your offer to a person? Just want your honest opinion, because it sounds logical but how are you going to track 1000 people if they are going to buy your product or not? What if they take the money, signup, and leave???
The cost is very low through services like Mechanical Turk. Typically you'd ask them to complete a survey on usability of your site -- you get some useful feedback from them, and sometimes they return as users themselves.
But do you get paying users from a site like that? If I'm anonymously filling out surveys for $4 per hour I'm probably not in the target audience for your $10 per month SaaS service or a particularly prolific purchaser via affiliate links.
Does anyone have any actual success stories in that area?
These are things that have worked for me on a tiny budget / evenings+weekend projects.
1. Depending on resources you have, target a niche where those resources will have an impact (focus in on blocks of 5% to 10% of your demographic) - facebook is ideal for this sort of targeting.
2. If you have a holding page, make joining your Facebook page / twitter acct the next step after submitting email. e.g. "Follow our Facebook page for early access beta codes"
3. Get chatting in forums that are related to your business.
This should be among your first steps: Reach out to the bloggers. Tell them about your app and if they are interested, they'll make your app reach out to several hundred or thousands of people.
Not strictly a webapp, but I love what Balsamiq did with Mockups - gave copies away to anyone who blogged a review. Great for spreading the word and a fantastic way of legitimate link-building.
At Social Tables - seating charts for events made easy - we picked a very early group of people to market to who could benefit from our app: brides. Today, we have over 1,000 users (we've been quiet for the past 1 month as we contemplate our future). Here's what worked:
1) Guerrilla Marketing - We found real life events that catered toward brides. For example, the Running of the Brides is an annual wedding dress sale hosted by Filene's Basement, so we showed up really early in the morning to talk to brides waiting in line.
2) Social Media Targeting - We monitored specific keywords "wedding & seating chart" and "just got engaged" and replied to each of those users telling them there was an easier way to create seating charts. We also participated in Twitter chats (here's a list of chats: https://docs.google.com/spreadsheet/ccc?key=0AhisaMy5TGiwcnV...) and people got intrigued. Finally, we actively tweeted using conference hashtags during conferences that had our target audience.
1. Referrals, referrals, referrals. People loving the product has been by far the best way to promote it. I don't mean affiliate sales (where people are incented to refer), just the garden variety friend telling a friend kind. Nothing wrong with affiliates, of course, just a different thing.
2. SEO, to a smaller degree. When people say "SEO", I usually roll my eyes, cause it's often a non-answer. "Get lots of traffic by writing great viral content". Which is essentially a harder problem than promoting your web app. But having said that, at least from a search engine standpoint, it's something that pays dividends slowly, over time.
3. Banner ads/Google Ads - not particlarly effective, and something of a negative ROI investment, but this was good early on to get a feel for what kind of messaging worked best, and what sort of conversion rates were likely from direct ads. So I'd suggest using these to learn, not as a sustainable customer acquisition strategy, unless your price point supports it.
4. Press/bloggers - we got some writeups by a few bloggers, which generated some short term traffic (usually a week or so), then fell off dramatically. Again, good for SEO, and nice to get written about, but this hasn't been a consistent or reliable traffic source.
5. Web app directory/startup directory sites - good for short term launch traffic, generating awareness, etc., but these directories seem more noisy and less relevant over time.
2)SEO. I think you're confusing SEO with content marketing. Content marketing, like having a blog with great content, is only a portion of SEO, albeit the hardest portion.
We are in the consumer-social space (http://boothchat.com) so we need to go out in the wild and find our customers. I'll talk about the first 2-3 weeks of starting up.
At the very beginning you'll need to do direct "sales". Apart from any ongoing efforts to attract press, SEO, SEM, etc, at the beginning you'll have to go out there and beg.
Locate your target audience and create campaigns. These campaigns should create you leads, which you'll have to turn into accounts and then customers... I'm talking like a salesperson here because the principle is the same. Were i mention 'accounts' imagine visitors to your website, where i mention 'customers' imagine those visitors converting to users.
E.g. specific search for relevant to your startup keywords on Twitter. Then engage with these users both from your personal and company twitter account. Never "sell" directly, rather try to get into the conversation.
Do that in a systematic way for a couple of weeks and soon you'll have your first hundred users. Of course this method does not scale, but by the time you're done with it hopefully your other efforts (press, SEO, etc) will start to kick in and you'll move to a whole new game...
A friend of mine took out an ad on The Deck (http://decknetwork.net/) when he launched his app. It produced quality traffic that converted into active users. It also opened some doors with people who could help him promote the app reaching out to him, including his app in a bundle, etc. I thought the cost was steep (~$8000 or so) but it seemed to pay off.
2) SEM - we buy keywords on AdWords, and, the critical part, we monitor signups as conversions to be able to track those clicks that actually convert. What we learnt in our case after spending hundreds of dollars: the clicks from the content network were cheaper but we never got a conversion from them, while those on the search pages performed quite well. We also zoomed into several other characteristics of converting clicks, which lowered our price per conversion (i.e. Thursday was from a long shoot our lowest performing day so we stopped advertising during this day etc).
The key to all those channels is to go through a 3-step cycle continuously: implement, measure and learn. Implement the traffic acquisition channels you can imagine, measure the effort and the results you get (clicks, conversions), compute the relevant acquisition price for each channel, learn from your data and zoom into (segment) those well-performing channels hoping to find an even-better performing niche. And repeat.
When i launched http://www.mizu-voip.com/ I have spent ~2 days on forums to mention about it, i wrote 2 blog entry and nothing more. Since then (a few years ago) we haven't made any new effort and we have just enough customers.
So my vote is on: useful content
While you're developing your app, keep reading Hacker News for comments on posts related to what you're working on.
For each relevant comment, jot down the comment link, author name and email address (look at their HN profile or links therein) and write a personal response, then and there, referencing their comment (give the link), and why they may be interested in your app, be specific, and also point out where your app differs from what they were talking about (it probably will). Use "Re: Your HN comment" as the subject.
When you launch, you will have a whole lot of personal, relevant emails to send to people who have already expressed interest indirectly. Don't send them all at once. Send them one by one, day by day. You may learn something as you go that you will then be able to incorporate into subsequent emails.
Another decent way which wasn't mentioned here so far is to comment on other blogs and pages with similar content. Not only is it a boost for SEO but, if your app is related to the post, people who read the comments will click through if relevant.
In SEO a main strategy is actually doing this, blackhatters use software that automatically posts comments on related blogs, but the whitehat (clean) method is to do it manually, and it works. Try to comment on as many high quality blogs as possible (high Page Rank).
Tip: Try to use your keyword for your name so it is anchor text, although some blogs might not approve your comment because of that.
1. Tried Press Release company that says they will push your articles out to thousands of media sources - didn't work as well as we hoped, because they do just what they say: "push the article out in a feed", no guarantees it will even be picked up. I'd be careful with this one.
2. Contacted relevant bloggers - works pretty well. You need to find relevant bloggers so your web app is in line with their interests. Then they will likely write about you.
3. SEM - Google adwords. This can work, depending on the cost of your keywords. For popular keywords (eg. "Social media") this may be too expensive to see any results at all. It's a great way to test out initial response to your web app and test the overall market demand. Depending on your revenue model, if you can figure out how to set your adwords budget so that you have a low enough average cost of acquiring a customer, you can have great results.
4. Blogging - can be VERY effective if you keep generating relevant information/content, especially in the long term for organic search engine optimization. Don't dis-count the use of Twitter / Facebook, to promote your articles, re-tweet, etc. This takes time and you might not see results right away.
5. Try a social-media advertising app - of course we use our own product! Yes, a shameless plug, but depending on your webapp and target market (great for apps targeting the younger generation), investing in social media marketing may be a great way to get users. Check out our platform http://www.incentibox.com/ - you can set up contest or rewards program in minutes and get your visitors to help spread the word amongst their friends. It's always refreshing to hear that people signed up because of word-of-mouth!
6. Cold email / cold call - This imho is the best way to get INSTANT feedback. To start, call / email 20 ppl a day, and see if there's any interest. If yes, then it's a numbers game, and you should invest more time into this.
I would suggest trying all that you can think of for promoting. In the beginning it will always seem like guerrilla marketing - it pretty much is! But hopefully that will lead you to discover which methods work for you and which don't. Good luck!
SEO and SEM are must. Working on both for our site www.Pawrks.com. Still on launch page as we are cranking the code for the other pages we are giving extra attention to meta tags (any suggestions welcome)
Also extensively canvassing with Facebook friends and twitter buddies to spread the word around.
Media coverage will be important just when we launch with all glory.
Something that has helped us, a little more in the e-commerce space, but listing your phone number definately drives business. We are bootstrapped, but let the number forward to our cells. All three partners pick up the phone, gives good connections with customers and allows us to do a good pitch and eleviate doubts.
For Intercom (http://intercom.io) blogging has been our most effective weapon thus far. We'll give advertising a go soon, just to compare. But right now it looks like a good article that's related to the product drives readers, which we try to then funnel into the site.
One thing that always worked for me is writing. I write a lot- emails, blogs, guest posts, tweets. It tends to get you a following that not only gives you a market to promote to but people to build for.
twitter is the most powerful tool if used properly. you can cultivate a rapport that can translate into a relationship before you know it...and for companies like ours that are completely outside of the heart of the action, it's allowed us to stay somewhat attached.
What field is it in? For ours (http://feefighters.com), which is b2b app, we have a 6 pronged attack which works pretty well:
1) SEO - people find us when they search for credit card processing and lots of long tail keywords. This is a long term thing but completely worth it. Make sure all of your pages are optimized for SEO.
2) SEM - we were buying keywords on google/bing/yahoo. Facebook has been less effective for us since we're b2b (but we tried it).
3) We get media coverage. We hustle and email and tweet a lot of reporters, etc, try to get interviews. Try to help them out all the time, refer friends businesses, etc. It works (http://feefighters.com/press - page not quite up to date). We paid a PR firm $5,000 a month. It didn't work.
4) We try to write interesting content on our blog/twitter (http://feefighters.com/blog). People link to it and we have a lot of subscribers who have nothing to do with our main business, but they tell their friends. We also do infographics. I personally think they are sort of played out (it was cool when you saw a link to one every few days but now they are everywhere), but they can still work WHEN THEY ARE GOOD and actually explain something well. We have some good ones and some that we aren't proud of: http://feefighters.com/blog/infographics/ - good: tech bubble... bad: restaurant one
5) Business Development - make deals with people in a similar space to sell your app
6) We let anyone refer their friends to FeeFighters and get paid $25 for it: https://feefighters.com/signup-or-login-to-refer-your-friend... It works... people want to refer us anyway, but this gives them an added incentive that makes sense to us financially. We use Amazon.com giftcards because they are the closest thing to cash we can think of that allows us to purchase it on our credit card and send via email to anyone - PayPal is annoying.
These things obviously work better for a particular type of app (one that is the sole focus of your time and makes you money), but some of these things are pretty universal.
"3) We get media coverage. We hustle and email and tweet a lot of reporters, etc, try to get interviews. Try to help them out all the time, refer friends businesses, etc. It works (http://feefighters.com/press - page not quite up to date). We paid a PR firm $5,000 a month. It didn't work."
In my day job, we had a similar lack of success with a $5k PR firm. Lots of money, some press releases and really little to no press coverage and absolutely zero new business.
At my small startup, I hustle and write tons of emails to every site I can think of that's mildly relevant and we've gotten a level of coverage we're happy with even if its just me firing off form emails in my spare few hours a week. (We've even managed to get a little radio coverage).
This is one way. :) And I'm not being cynical. You should take these kinds of opportunities. Of course, you need to strike a balance, but I think pitdesi did that pretty well. You've got to hustle.
Taking my own advice... One of the things that brings people to http://hubski.com (a social aggregation site) is original content. I like to write, and I found that when I wrote on hubski, that content brought quite a bit of traffic. If you are creating in the social space, IMHO you need to think of your site as a restaurant. Above everything else, you need to have quality food. You can get tons of traffic, but if you don't have quality food, people won't come back. It's easier said than done, but I found that contributing my own original content seemed to provide a value that few other things did. I've come to the opinion that quality is everything. The little things count. Be tough with yourself, and listen to criticism.
Ask yourself: "Do I like my app? and What don't I like about my app?" everyday. If you love your app, it will be infinitely easier for you to promote. Make sure you love your app before you start putting serious resources into promoting it. If you love your app, traffic to your site will likely be more effective.
BTW, this post is at #3 samrat. This would be a very good time to tell us what your app is! :)
EDIT: Another thing to try: To get some objective feedback on first impressions, you might want to try stumbleupon. People can vote on your site when they stumble it, and you can look at the average score of your site. IMO I don't think that SU is an effective way to advertise, but that does provide a measure for first impressions. If your score is low, you know you need to work on your landing page.
I wouldn't underestimate facebook for b2b. The users that see the ads still work at businesses. I have had very good success using these for my b2b application.
I used the "likes" targeting in the facebook ads demographics to target occupations that my product is aimed at. I also targeted relevant english speaking countries.
I have tried quite a few different styles of ads, but individual ads for each occupation that were specifically targeted has the best results. I guess I would advise creating many ads, and wording them specifically for each demographic you want to target.
I also tried various pictures, but ultimately a screenshot of my app was the most successful.
The majority of my users so far were acquired via the facebook advertising, it has been my most successful strategy.
6) Referral for $25 ... people want to refer us anyway.
Without the fee, people would refer you anyway, mostly anonymously. So the $25 fee is a way to document where your referrals come from. That sounds like a good buy.
1) Inbound marketing. Have a solid blog and social media plan in place, which doesn't ignore SEO and link building. (My upcoming book for The Pragmatic Bookshelf is exactly for people in your position: http://technicalblogging.com. Sorry for the plug, but hey, we are talking about promotion :)
2) Hustling. Get in touch with as many bloggers and mailing list owners in your niche as possible, offer to guest blog, reach out to journalists with a compelling story, and so on. Do the heavy work so that all they have to do is say YES. This is at the core of hustling.
3) Paid advertising. Online and offline advertisement can be amazing tools to grow your business. You need to be careful though, and optimize your campaigns or it's very easy to bleed money.
4) Affiliates and rewarded referrals. Give an incentive to those who want to promote your app. You can give monetary compensation to your affiliates or provide some perks to your users (e.g., free premium account for you when you refer someone who buys a premium subscription).