I think it's great to brainstorm, and have a bank of marketing ideas that you can pull from. With a startup, things change fast, so I'm not sure a 'comprehensive time-phased marketing plan' is the route to go.
I do, but marketing is my job decription at the startup I work for ( avanoo.com ).
I think it's important to set at least rudimentary benchmarks/milestones in terms of growth and brand recognition.
After that, throw a bunch of stuff on the wall and see what sticks. The few ideas with the most ROI in terms of 1. traffic and 2. user retention should be at the forefront of your future strategies.
This may not sound like much of a plan, but as long as you have a mini-strategy in place for every one of your marketing efforts, and as long as you understand and, if possible, participate in the community you are marketing to, the try-everything approach should work.
Plans? We don't need no stinkin' plans (particularly not a time-phased one).
Seriously: Marketing success (like software development success) seems to be highly correlated with getting something out there and iterating as frequently as possible based on feedback.
Writing a plan is fine (if that floats your boat), but it often creates the delusion that you can actually control and predict how things are going to go.
"Failure to plan is to plan for failure." ... Writing a plan is fine does not creates the delusion that that one can actually control and predict how things are going to go. ... It gives the implementers an concept what might be happening. ... From a high level but pragmatic viewpoint, it is what process of writing the plan are you using that is failing you. If you are writing it from a low level, you will FAIL.
Planning requires people with wisdom, vision and conscious experience. . . . A person who has no conscious of what is going on, usually live on the seat of their pants. ... Reader! Who is planning for your company? Do they know the big picture from a "top down tangible viewpoint"? (Where we are at, We call it a Tangible Vision.) From the strategic classics: One who excels at warfare will await events in the situation without making any movements. When he sees he can be victorious he will arise; if he see he cannot be victorious he will desist. Thus it is said he doesn't have any fear, he doesn't vacillate. Of many harms that can beset any army, vacillations is the greatest. Of disasters that can befall an army, none surpasses doubt. - Six Secret Teachings, 26
If you manage to jott down 10 ways to market your idea and have a timeline i think its a good idea. everyone knows you cannot predict what is going to happen but that doesnt mean u cannot plan for the future.