Much as I personally dislike Paris Hilton and the related series of celebrities (the Kardashians come to mind), I have to respect the business acumen.

A lot of people have made sex tapes, some of them professionally, but very few have made that much money from it. Partially that's because they were rich already, and maybe they just had a good manager/marketer/whatever, but they still managed to make a lot of money from something that is not typically well compensated.