Reviews are, by their nature, personal opinions. I don't see how you can put a framework of fraud protection around that. Maybe in extreme marginal cases, but for the central idea of reviews, it just doesn't work.
Where there’s a will, there’s a way. This isn’t about policing valid opinions, it’s about identifying what is currently a massive and obvious trend of actual fraud. Requiring authentication for reviews and products is the first step, and isn’t that hard, we know how to do it already. Amazon is choosing to allow reviews and products by people they know are bad actors. They look the other way and allow fruadsters to be anonymous because there are no consequences yet. They’re not imposing consequences on fraudulent sellers or reviewers, even though they could.
I don’t believe the main problem is that they don’t know how to identify fraud, I think the main problem is they don’t have any real incentive to.
