Using Duck Duck Go, nearly all my top search results are Yelp, and that is at times enough to make me use Google. (Yes, for every search I could type -yelp but that gets painful.) It's clear that the way Yelp indexes, that Google is doing something to push it down. The question is whether that is purely to squash their competition, or because people don't actually want Yelp results. I'm not suggesting the former is not the case.