Prof. Robert Cialdini author of "Influence" says: " People follow the lead of many others." Richard Shotton who references Cialdini's work in his book "The Choice Factory" says: "People are deeply influenced by others." Social proof is a highly effective strategy for businesses. It can even help convince people to do something that they probably don't want to. Like paying their taxes on time. Getting regular 5-star Google reviews lets people know your business is popular. In the words of Cialdini "it reduces their uncertainty and gets them off the sidelines". If you want to generate consistent high quality leads then you'll want to start building social proof.