said by cableties :

Storage venues like Megaupload, Rapidshare, etc, make their money in illegal file sharing (under the guise of Upload for free, download per fee, along with advertising/subscription model).
I don't know anyone that uses these service for anything legal.
Yet RS, MU, ... do compensate for traffic, etc. Again, I do not know anyone that makes money, but I can "guess" that if one person uploads files of a desirable adult movie, and others have accounts and download that file, you can make some change on the traffic and/or referrals.
So how do these sites make money? Traffic through ISPs to keep fat-pipe costs low? Advertising metrics? Well, for starters you can upload then share the files, earn points with all the upload traffic, convert those points into accounts, and then sell those accounts for money (paypal...). Pyramid!