I do a decent amount with TopBucks and I would guess that either iTeens or Ultravideos would be your best bet.
Ultravideos is a great seller for me - and iTeens converts very well. I can't say for sure with my celebrity traffic - as it is hard to say where my sales come from. I haven't tried the porn star niche yet (will be this week), but they have a new porn star site that might work too.
Also, I noticed that they had "celebrity site" listed as one of the options people could vote for as a new site (out of 5 or so). They have recently implemented three of these - I wouldn't be suprised if a celebrity site is in the works (that is what I voted for)....
You can always try writing Allison at TopBucks. She seems very willing to help.
UltraVideos I think I could sell on any site except "I hate videos". I have been using tour 2 for UltraVideos (although Allison suggests tour 4 might work better) and I have been using tours 2 and 3 for iTeens lately.
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