The only membership i buy is from rapidshare and i have done so for the last 3 years.

But i did buy a 24hour trial to some shit porn site about 10 years ago.
If you know how to search google you can find most clips/dvds/pics from most porn sites. However the was one or 2 clips that i was finding hard to get, and was tempted to join the site to get them. But i just waited and Eventually the do turn up on rapid or other file sharing sites like it.
Other then maybe live web cams of your favorite stars, i dont see what the rush is to join a site for its memberhip. unless you are one of them people who must have everything before anyone else? i dont see why paying a membership fee is worth it?
If i had the cash to burn i would probley join afew sites, but i dont so im happy with getting stuff the file sharing way.
Im sure the will be members who will post why the pay for sites.