The textbook answer is to start in a niche. What you need is a large proportion of the market. Aim at a small market and you can be a big fish in a small pond quickly. Then you can expand from there.
Some examples:
Gmail: Google geeks -> well-connected geeks -> all geeks -> non-geeks
Facebook: Harvard -> Ivy League -> all US universities -> etc.
Stack Overflow: Joel's blog readers -> programmers at large.
A good proportion of success stories contain a similar history, and for good reason. It is particularly easy to see why this is so effective by considering Facebook.
Some examples:
Gmail: Google geeks -> well-connected geeks -> all geeks -> non-geeks
Facebook: Harvard -> Ivy League -> all US universities -> etc.
Stack Overflow: Joel's blog readers -> programmers at large.
A good proportion of success stories contain a similar history, and for good reason. It is particularly easy to see why this is so effective by considering Facebook.