I wrote something up real quick one night a couple years ago and submitted it to poetry.com out of boredom coupled with brief flash of inspiration.
I'd forgotten about it, then about 2 months later I got a letter from them saying that they were having a book published, and that my poem was a standout. They wanted it for their book. I'd only have to pay them $80 (if I remember correctly, might have been more) to get it published, and for my copy of the book!
Smelled pretty fishy to me. I thought about it for 10 minutes and decided it was a crock of doo.
I do have to admit, however, that the thought of being able to remark offhand "Yeah, my work has been published," kind of attracted me.

That's probably what they were counting on.