How does Vine increase your sales?

We have product that has plenty of reviews, but Amazon recommends Vine reviews. Unless you have only a handful of reviews, I can't see how Amazon's recommendations to do Vine can increase your sales. One or even ten Vine reviews can't help you if this is just a matter of submitting your products blindly to randomly use the product. Also, maybe it's just me but if I see a Vine review, I get the feeling the product isn't selling well and the sellers are buying reviews through free products. Am I wrong? Is there some other benefit other than a possible positive review? From what I read, I really don't see one.