These kinds of ads aside, I've also seen offers of free shit from amazon sellers in exchange for positive reviews, "legal"/unscheduled drug analogues, flavored nitrous (free shipping!), unrestricted gambling/prediction markets, and oddly enough cellular/wifi jammers where the ad was specifically targeting semi truck drivers (I do not drive a semi truck, gamble, or search for unscheduled drug analogues, nor do I have an active amazon account)