Not to mention, most of the heavier traffic and well known paysites do not censor their sample tour page images. I mean, take a look at
Reality Kings -
ATK Exotics -
Milf Hunter -
Simons Scans -
Abby Winters - among many others. And they also have uncensored promo content too. They don't bother with censoring their tour pages content and I am sure that they still do very well.
I guess it just depends on the type of site that you are running. When it comes to a solo girl site, I guess it's not that bad of an idea to censor a LITTLE on the tour pages but for the most part, you want to show the surfer what he is going to get after signing up with the site. If it were me and I operated a one girl solo site, I would still choose to not censor the content though.