The best reviews come from your current and satisfied clients. Keep in mind that Yelp has an algorithm that will refrain from publishing reviews by new member profiles, in an effort to keep their platform honest and genuine. Second, I would assume you are in a local product or service vertical, if you are looking to build a Yelp profile. If you don't own a restaurant or retail shop, the value of Yelp is next to zero.
The problem with Yelp is they are selective when it comes to reviews. They will post two bad reviews then hide and not recommend some 40 reviews with very favorable ratings. But if you sign up and pay them they can help with that ?