Illegal Tender

Every once in a while, I get mail from companies offering a credit card or membership in a super-exclusive top secret book club or discount hotel society, and inside the envelope, accompanying the introductory letter, is a shiny cardboard or flimsy plastic card that looks like an actual credit card. Like this:

Cut me out and use me!
And every one of these sample cards includes a disclaimer either on its face or on its reverse side, like this:

Don't cut me out and use me!
Now, what I don’t get is this: Is someone really going to try to pass one of these cards off as the real thing? And even if they’re numbskulled enough to try to do so, is a cashier or anyone else to whom the card is presented, really going to accept the card? (Uhhh …) They are not plastic; they are not embossed; they do not have a magnetic strip to swipe.
And it’s not just these cards. I’ve also seen play money that included disclaimers. Stuff that in no way resembles the real thing, such as a pink, deckled-edge $12 bill sporting the face of Jan Brady, or an oversized, way too green fun-dollar bill with some schmoe’s nephew’s face peering out from the center, with a NOT FOR LEGAL TENDER reminder/caveat.
I guess I shouldn’t be surprised. I mean, after all, I did paid for my college education with all the mesh sacks of gold-foil-wrapped chocolate Hanukkah “gelt” I could carry and put the balance on my Banana Splits fan club membership card, so you never do know.