Really terrific article on how Yelp builds communities: How to Expand Your Startup Out of Your Home Country - Tech Europe - WSJ:
It seems really simple, but there are tons of little things you have to do to make it work. And you need a lot of patience. At Ben's Friends, we have a lot of faith in the "slow-build" communities. Some of our largest and most powerful communities were real slow growers at first. But building that slow base creates tremendous staying power.