I recently was looking for some widget on amazon and one of the chinese “brands” came up. They had 300+ reviews and 4.5 stars so I thought it had to at least be decent. But then I clicked through to read some of the reviews, and was surprised to see that there were many 1 to 3 star reviews, but none of them were counted. They all had strikethrough on the text, and then an explanation from amazon saying “because this was fulfilled by amazon, we take responsibility for this failure”.

A lot of the time when i visit such a listing all the good reviews turn out to be for some unrelated product, the listing was clearly swapped.