How would you launch a Yelp-like site?
apsurd: I think there are a lot of small businesses that still don't have websites. Or they have static, aging websites simply because they don't have the resources to commit to their internet venture.My startup is working on getting businesses online, from the ground up in a simplistic yet proactive "learn as you go" type approach.Anyway the point is your service is very useful to businesses because it generates content FOR them. When businesses get started online, generally all they want is EXPOSURE. They ask things like "how do i get on google", how do i get "clicks", "who do i pay to get customers" ... 
Your service allows greater exposure through organic content growth...I would suggest you relate this to small business who may or may not have a website. Tell them to encourage existing customers to use your service. Their online exposure will grow and its a win/win. Prepare quick benefit packages and "getting started" guides for businesses. Encourage THEM to do the promoting and since it is in their best interest, it just might yield results.