A huge challenge for user-generated websites is overcoming the chicken-and-egg problem: attracting users and contributors when you are starting with zero content. One way to approach this challenge is to use what Geoffrey Moore calls the bowling pin strategy: find a niche where the chicken-and-egg problem is more easily overcome and then find ways to hop from that niche to other niches and eventually to the broader market.
Facebook executed the bowling pin strategy brilliantly by starting at Harvard and then spreading out to other colleges and eventually the general public. If Facebook started out with, say, 1000 users spread randomly across the world, it wouldn’t have been very useful to anyone. But having the first 1000 users at Harvard made it extremely useful to Harvard students. Those students in turn had friends at other colleges, allowing Facebook to hop from one school to another.
Yelp also used a bowling pin strategy by focusing first on getting critical mass in one location – San Francisco – and then expanding out from there. They also focused on activities that (at the time) social networking users favored: dining out, clubbing and shopping. Contrast this to their direct competitors that were started around the same time, were equally well funded, yet have been far less successful.
How do you identify a good initial niche? First, it has to be a true community – people who have shared interests and frequently interact with one another. They should also have a particularly strong need for your product to be willing to put up with an initial lack of content. Stack Overflow chose programmers as their first niche, presumably because that’s a community where the Stack Overflow founders were influential and where the competing websites weren’t satisfying demand. Quora chose technology investors and entrepreneurs, presumably also because that’s where the founders were influential and well connected. Both of these niches tend to be very active online and are likely to have have many other interests, hence the spillover potential into other niches is high. (Stack Overflow’s cooking site is growing nicely – many of the initial users are programmers who crossed over).
Location based services like Foursquare started out focused primarily on dense cities like New York City where users are more likely to serendipitously bump into friends or use tips to discover new things. Facebook has such massive scale that it is able to roll out its LBS product (Places) to 500M users at once and not bother with a niche strategy. Presumably certain groups are more likely to use Facebook check-ins than others, but with Facebook’s scale they can let the users figure this out instead of having to plan it deliberately. That said, history suggests that big companies who rely on this “carpet bombing strategy” are often upended by focused startups who take over one niche at a time.