1) Identify what group of people (professional group, culture, etc) would benefit most from your product.
2) Seed early to this group and use them as a sounding board. Build a relationship with them. Focus on solving problems for this user base first.
3) Figure out a way to drive and capture the enthusiasm of this group and leverage it outside when you launch. Your PR will not just point to a product, but a social group using your product in a compelling way. Your feature list is now a benefit story.
this is very generic things to do to begin with - the idea is to know what exactly pg recommends to use as a powerful tool, such as PR firms, facebook, twitter, blogs, buying email list (not spam), google ads, display/banner advertising, other social media etc. The marketing scene is changing extremely fast - what works today may not work tomorrow - so it would be interesting to know what pg suggest if any company has to start today.
Honestly, focus on the product first. If you fulfill a strong need for a defined group of people they will do a lot of the talking for you–in a much more authentic way then you ever could.
Once you get their support you can put your small budget behind the stories they are telling around your product.
Your question is very generic, too. Startups targeting consumers are different from startups targeting enterprises. What users do you address? What about the business model you have in mind? The size of your market? Has your product viral features built in? etc, etc, etc. I think it is presumptuous to believe that there is a single marketing strategy that may fit all startups in the world...
true, one size can't fit all - though i think major YC cos. are mass consumer base (than enterprise soln.) so buzz creation tool for most of them will be more or less the same (may be i'm wrong).
2) Seed early to this group and use them as a sounding board. Build a relationship with them. Focus on solving problems for this user base first.
3) Figure out a way to drive and capture the enthusiasm of this group and leverage it outside when you launch. Your PR will not just point to a product, but a social group using your product in a compelling way. Your feature list is now a benefit story.