Notice that niche shopping sites don’t have reviews. Bigger sites have reviews but they don’t get gamed. Without affiliates or listing products like Amazon, there is no way for the spammers to make money.
I’m surprised that places like Walmart or Target haven’t gotten burned by cross listings. They could drop the program and advertise as alternative to Amazon. If Amazon had “sold by Amazon” filter, it would be a lot more usable.
I think that's the reason why Allegro is market leader in Poland and Amazon is far, far away. I get really frustrated when I try to find anything on Amazon, sometimes to the point of thinking "how the hell they became so big with this shitty search?". When I search anything on allegro.pl it almost always return me products I search for and support tons of filters (and return actually nothing when they don't have it).
I’m surprised that places like Walmart or Target haven’t gotten burned by cross listings. They could drop the program and advertise as alternative to Amazon. If Amazon had “sold by Amazon” filter, it would be a lot more usable.