Jokes on them, I never look at 5 or 1 star reviews. By convention I think rating systems are fundamentally flawed in that they are anything but a ubiquitous concept. The people struggling to piece together how they feel about something in a binary construct generally have the most insightful comments. There's no way to stop someone from gaming the system though. If the economic incentive is to cheat, cheaters gonna cheat. Eventually plugins like FakeSpot will become as common as ad blockers, imo.