Several ways:
1. Repurposing product listings for something unrelated and keeping the old sales data and reviews
2. Merging product listings to aggregate unrelated sales data and reviews
3. Fake reviews that were unrelated to the product all along
> 1. Repurposing product listings for something unrelated and keeping the old sales data and reviews
Sure - but this seems trivially solvable by Amazon - you can't tell that a product listing for a knife set is not a tech product??
> 2. Merging product listings to aggregate unrelated sales data and reviews
Again - def happens I think. But can't these go through some type of review? The ones I've seen are WAY off when you look deeper.
> 3. Fake reviews that were unrelated to the product all along
This is harder, I'd have 2 amazon staff review higher volume products.
Any system Amazon puts in place will have a lot of false positives that require human review. And that is entirely aside from the fact that underhanded sellers will try to flood such a system with automated disputes until Amazon relents.
> The ones I've seen are WAY off when you look deeper.
You're assuming these disparate merges happen in a single step.
What I don't get is that on Amazon I've purchased 10's to 100's of thousands in product (was an early user, business account admin etc). Of all the reviews that SHOULD have credibility, someone who doesn't review a lot and buys a TON of product - you think would be slightly credible?
Instead, for those (few) times I've posted a clearly negative review - gone for whatever reason. If you buy enough from Amazon, especially in last 5 years or so, you got some total absolute trash in there.
"Genuine" Apple products absolutely totally 100% fake trash. How amazon's supply chain thinks these are legit is mind boggling.
I've had such bad luck with "genuine" and "oem" battery replacements I've given up - most of these things are just crap scam stuff.
I'm actually curious how this even happens sometimes, some of the used crap was BADLY used, think of a bunch of electric pencil sharpeners for an office, all "new" that are filled with old pencil shavings, scratches etc etc. Product reviews that when you go back to understand how the piece of trash product got 5 stars you realize the reviews DO NOT EVEN RELATE TO THE PRODUCT you purchased. I mean, how does this even happen?
So you get out the review - hey, this things was garbage, and many of the 5 star reviews were for a knife set it looks like instead of a powerbank. Review rejected :)