I think you can assume that Amazon operates in its own best interest. If fake reviews were hurting sales, it'd stop them within weeks. I'm guessing, for the time being, they're helping sales. Although, I haven't bought anything on Amazon in 3 years now, and I never will again. I think this problem is creating HUGE long-term downsides. Those are a lot tougher to calculate/quantify than the short-term benefits, though.