eCampus.com: Worth it?

Lethargic that I am, I still have some textbooks from college lying around my room. I left them up on half.com since last year, and never gave them another thought. Once in a while, I get a "please ship..." email, but I still have enough books around to notice as I was doing my ritualistic winter cleaning. Now I'm looking for alternative (read: more successful) ways to sell my textbooks off.

I was checking out ecampus.com's BuyBack system today, and I decided to price a few books to test. The Diary of Anne Frank is selling for $3.07, but ecampus will buy it from me for $0.50...minus the $1.94 mediamail label they "give" you for selling them your books, that's a little over a 60% profit. And I'm sure they get a shipping discount from USPS. $0.50 isn't enough to make me run to the post office to send my books out. I'm better off donating these books...but it makes me wonder if I shouldn't start my own BuyBack program.