merchandise offered as an incentive to try products from catalog merchant Fingerhut (spend x dollars and get 1 gift, spend x more dollars and get 2 gifts, et cetera; they were always yours to keep even if you decided to return the product you'd ordered), they were always photographed beautifully and lyrically described, but extremely disappointing once you actually saw them.
(2) something that looks or sounds really good, interesting or worthwhile that can be accomplished with little or no cost or effort, but ends up being a complete bust. An alliterative way of saying "you get what you pay for
(3) something that fails to live up to your expectations
Ferd: Hey, Jules, some guy was handing out free passes to go see his new action flick! Want to come?
Jules: Hells, yeah!
Ferd: I want my 90 minutes back! What a free gift from Fingerhut that turned out to be!
Susan: Hmmm, the infomercial made this Bosom
Buddy workout seem effortless, but my boobs are no bigger and I'm sore as hell. That's the last time I go for a free gift from Fingerhut!