Sell Your Textbooks With Facebook

Felix Wang had a great idea to let users post their used textbooks on their profile. As of now there are only 37 people that have added the application, but I could see this as being highly useful. The only question is would people prefer using a designated textbook application or will they go ahead and post their book for sale in the classifieds? For the time being this application is just an extension of ISellMyTextbook.com