It seems that Yelp's play to business owners is selling them sponsored advertising. They did reach out to me about 6 months ago to share with me how the business owner's non-paid account works complete with a quick Yelp walk through. But the pitch was simply, you can do much better, plus get unlocked/enhanced features if you pay to play. Mind you I'm not opposed to this. I've been a Yelper for a long time now and I see the value. It's just, when you look at what Google is doing with Place Pages, it seems a bit poorly executed when Google offers much more to work with, and for free. The difference is that Google wants you to flesh out a profile and appear for you own relevant search terms (pay to play on keywords). Not just positioning goes to those who pay.