"It is estimated that the average time a woman stays in porn is about ten months. In her honeymoon period, she might shoot as many as ten scenes in a week and can often keep up that pace—as long as her strength and sanity hold up—as she makes it around to every last porn company there is. This is usually accomplished in 45 days. Looking through a chunk of photos from 2005, I found that roughly 90 percent of the subjects were no longer in the business, including AVN's Best New Starlet of 2005, Cytherea."

http://fleshbot.com/sex/memories/popshots-of-the-week-flashback-edition-290318.php

Most chicks are just in it for fast cash.

45 days = $40k - $60k at 10 shoots a week... then POOF they're gone.

As it freaking should be. Way too many of these girls overstay their welcome by a long shot. I guess they get addicted to the money and attention. In a perfect porn world, each girl would do maybe 20 scenes and then leave. Personally, I don't need more than 2 or 3 scenes of any girl, if they are done right. After that, next!