If I were Google, Yelp, or Facebook, I'd give serious consideration to selling local businesses pre-created, theme-able web sites on a subscription basis. They already have essentially all the content such sites would need, and better designers than most small businesses would have access to.

I regularly run into local places that use their Facebook page as their de facto virtual storefront, but that format could be much better customized for individual business varieties' needs, even putting aside the limitations of living in Facebook's garden.