Given Yelp's size, why doesn't it employ some collaborative filtering options? In general I don't care about everyone's reviews (especially of restaurants). But it would be interesting to know -- for people who like White Castle, McDonald's, and Denny's, but not Applebees -- what would they recommend. This is not the type of thing you could typically get by reading reviews by themselves (and maybe those people wouldn't do Yelp reviews in any case). But standalone reviews of things where taste is such a large component I find almost worthless. With that said dog training is probably something where taste plays a much smaller role.
There's a new mobile app called Ness (http://www.likeness.com) that's trying to do this. I happen to agree with you, so I really hope Ness can pull this off. I'd really like a recommendation service that knows my personal preferences.
