They also put “you’re a lucky customer” offer cards offering Amazon gift cards with the items. We emailed a hotmail account to get a $15 Amazon card for filling out a review. Then they offered an extra $10 to make it 5 star.
Couldn’t one make the review, take the money, then delete the review after redeeming the card?
I'd imagine you could but enough people just don't bother that it still ends up worth it.
And/or, the set of people who'd have qualms about leaving a fake review, but were perfectly willing to cheat a stranger out of $15, is empty. Not to mention, it would kill an opportunity for repeat business.