[andymurd]

Realise that massive success is not going to happen overnight.

Don't dismiss SEO because it will "take months to get ranked" - start pursuing SEO now and in a couple of months you can rank. If your idea is unique, that's great! Try to rank for the problems that people have, not how your app solves them.

While you're waiting for your SEO efforts to pay off, use PPC to refine your marketing message. Test, analyse, refine, repeat. PPC is an expensive way of getting users at first, but it's a cheap way of refining your marketing.

Finally, find people that are experiencing the problem that your app solves. Join and contribute to communities, sponsor competitions, write guest blog posts. Establish yourself before using the back-channels to Mashable/Techcrunch.

Do all this stuff for a couple of months and don't get downhearted if nothing pays off immediately. It's investment.