The resale of a timeshare is a legitimate business. Companies agree to advertise a timeshare for a fee on their websites. As with advertising, the membership doesn´t need to sell in order the fees to be legitimate. The difference between an honest timeshare resale company and a scam, is when the company falsely suggest they have a buyer waiting for their timeshare, or picture unrealistic, overoptimistic selling possibilities. These are good articles on how to use timeshares properly:

http://www.timesharescam.com/