Credit:
Zunafish is bringing back an old idea: online swaps. The trades are limited to certain types of items and each trade costs $1. From the NYTimes article:
The site...trades only one-for-one items within the same category — CD's, DVD's, VHS tapes, video games, audio books or paperback books. No item (for example, a seven-disc DVD set of the first season of the television series "24") is worth more than any another (say, a DVD of Peter Jackson's "King Kong").