Yelp is another bad one. I've been told that if someone reviews you on this service, they will call and try to sell you there services to improve your ratings. One office I know of refused, but then asked their patients to write reviews in Yelp. Well, they said that the company then "filtered" all of the good reviews out to another page, so when someone searched on them there was a low rating and it was based on mostly the bad reviews. I checked, and sure enough there are many good reviews filtered out. One positive reviewer even said her initial review was somehow deleted, so she was writing another one (which was of course filtered out.)
I went to another doctor that I know of and most of her negative reviews were filtered out. Maybe she is paying them. I don't know.
But people do read these and make decisions on them. I have had potential new patients email me and say they were canceling their appointment because of negative online reviews.
