In a recent FAQ spotted by Automaton, Housenka responded to a hypothetical of "I'll promote you, give me a Steam key" with a delightfully blunt: "Buy it, you piece of garbage." Or, as Automaton translates it from the original Japanese, "Buy the game, you piece of sh*t." I can't decide which I like better, honestly. The full FAQ is worth a read, if only for Housenka's sense of humour and an insight into the absurd questions independent devs get asked these days.
"Make this character's ass and thighs thicker," another frequent-question-asker demands, to which Housenka responds: "Accept her as she is." When asked by a phantom answer if the game will add sex, Housenka also proceeds to provide a link to DLsite, an online store that sells doujinshi—self-published manga comics that are often (though not always) pornographic in nature. "No sex. Please visit DLsite for that."
Many keys on such sites are bought with stolen credit cards. Publishers could disable these keys afterwards but most don't because it's not the sole fault of the buyer. That's another method of selling these keys, never Buffy them for an indie Dev or small studio, they could actually lose money if they need to charge back (including fees etc), for the 500 Trillion $ networth AAAAA-Publishers I cannot be bothered to pay 70$