The capture of rating agencies by the entities they would rate seems to be common if not inevitable given the incentives - the companies being rated have a strong financial incentive to fix their ratings while at the same time, the consumers don't pay for the service. So, the agencies eventually go after the only money in play and turn into a protection racket, and perhaps make room in the market for a new agency subject to the same incentives.
How would you change the incentives? The incentive for a restaurant to leave a fake review is much higher than the incentive for a customer to leave any review. For crowd sourced reviews, introducing a trust model opens the door to account selling/paid reviews. You can't really punish the bad actors or you open yourself to a different kind of abuse. You really need a PageRank equivalent for reviewers? Is there some feedback loop (like following clicks) to the things you recommended (and seeing engagement on that page from GA)?
