Card games - addicting?

I had a chance to play Diggity with my long-time friend Jeff the other day.  We played a couple of games that I won pretty easily.  I got better cards than he did in at least one of the games, but I think my success was mostly due to having played before. This confirmed my opinion that it takes a few plays to figure out what good strategies are in Diggity, which is neat - the game seems fairly simple at first glance, but I think there's more to it once you've played a few games to see how it goes.

Jeff (who's incidentally running for congress in Virgina) also fell pretty hard for my computer game, Snood, a number of years ago, and he commented that he found Diggity, like Snood, addicting.  I know people got addicted to Snood - they wrote to tell me about it, and I've been there myself, playing game after game past 2:00 a.m., either because I have something else I'm supposed to be doing, or because going to sleep seems so mundane.  I hadn't thought about card or board games in that way, though.  For one thing, you need a partner to play, so you can't be addicted the same way.  But I've had games I've played over and over - e.g. Lord of the Rings, and Egyptian Ratscrew - that I certainly was essentially addicted to.

If Diggity can do that for more folks than just Jeff, I'll be pretty happy.