I was once greatly disappointed by an item and left a very, very detailed review which reported the exact reasons for my dissatisfaction and all the various tests I made of the product that led me to my conclusion.

All my effort was for nothing. The vendor just delisted that item and re-listed it again, so no one would even read my review unless they bothered to read reviews for a delisted product.

I guess I could have re-posted my review in the new listing, but it was too much trouble, so I never bothered to do so.