I have been on Yelp going on 3 years now, which started cause I wanted to find a place that was safe for my dog Maggie who had multiple health problems. I took her to the vet hospital and was treated very poorly. I yelped that business and the next day contacted by the manager asking me how to make things better.
It was then on I decided to Yelp my reviews of places I have been to and share my reviews with others. Yelp is free and there is no reimbursement for being a Yelp Elite. However, you get to go to fancy events and learn about local places in town and businesses. Great site!