When unlimited amounts of explicit, well-produced pornographic material are available across the Internet, under the counter in bookstores and in a reasonable number of video stores, why is it that fleeting naked shots in movies still catch us?

From James Franco’s rear-shot swimming pool scene in Milk, to Gael Garcia Bernal’s bathtub fiasco in The Science of Sleep, to Emile Hirsch’s floating river shot in Into the Wild, brief nude shots often turn out to be the most memorable scenes from movies — not for artistic or cinematic value, but because they’re hot.

The 2007 Seth Rogan film Knocked Up featured a group of deadbeat roommates with an ambitious business plan to launch a website listing the timestamps on movie scenes with nudity. The idea is that a list of scenes with a famous actress’ nipple or bush is still of interest in a world of easy porn, and people would pay to access the site. Fleshofthestars.com was a fictional enterprise, but there’s no doubt that there’s truth beneath its concept and Hollywood producers allow those brief titillating scenes hoping it will increase a film’s popularity and earnings.

Perhaps it’s that porn stars are depersonalized and distant; we see them in the most intimate of settings but know nothing of their minds — and the ease of access desensitizes us and eliminates novelty.

Meanwhile, the “mainstream” status of movie actors helps the scene feel more artistic and less deviant. A character in a full-length feature is someone we have time grow to know or love just as much as a first date, making a fleeting soft cock shot more interesting than twenty minutes of hardcore action in a video elsewhere, even when the total nude appearance in a film is a fraction of a second and the angle is unflattering.