Actually, I think that's probably the only workable solution to the whole fake-review problem. The only reviews you should trust are the ones written either by

Actually, I think that's probably the only workable solution to the whole fake-review problem. The only reviews you should trust are the ones written either by people you already know and trust, or people who are trusted by people you trust, and so on. Currently, it's really easy to bribe a random person to write an anonymous review. If the maker of some product has to bribe a friend of mine in order to get me to buy that product, it's going to be a lot more work for a lot less gain. Eventually it starts to look a lot like a company bribing all of its customers at once to buy its products, which if they can pull that off and make money, more power to them I guess. The social media companies have the data and infrastructure to implement some sort of "product reviews weighted by the reviewer's proximity to you in the friend graph" feature, but I don't see users trusting Facebook or LinkedIn to be an impartial source of trustworthy reviews. (Also, a lot of Facebook friends aren't necessarily people you'd use for product recommendations, but that's a separate problem.)