A giveaway basically. If you have something you don't want or use anymore, and you feel like giving it to someone you know will want, use or enjoy it, you post it here and draw a name for the winner. Don't know where the term karma came from, but it's just a giveaway drawing.
Karma - "The effects of a person's actions that determine his/her destiny in his/her next incarnation." From Hinduism and Buddhism. Basically, what goes around comes around. For the purposes of this Forum, it's what TNDixieGirl said: a giveaway.
Post your karma any old time... Peops love them!!! I don't sign up for all unless I really want the "gift," but you will get lots of interest in whatever you offer.