How do upload sites afford to pay you?

Singapore
November 24, 2010 1:19am CST
How does sites like hotfile, filesonic, and filefactory afford to pay you per 1000 downloads? Is it due to the fact that out of 1000 epople a few most likely become premium memebers? As well as the sites have advertised to 1000 people? How was any of your experiences using this sites?
No responses