Well ALL of the content on my membership site at
http://www.girlsdotcom.com is temporary. I have no permanent content. At any given time, I have 25 "photo spreads" up (average about 300 photos per). When I add a new spread, the oldest one disappears. At the same time, I have some preview photos telling the members what's coming up. The scheduled updates are set six days apart. However, between the scheduled updates, I put up one or two bonus spreads, usually drawn from my rather huge library of photo sets. Between wanting to hang in there for the scheduled update and wanting to hang in there to see what surprises await them in the bonus updates, I keep the members interested. And this is a site with, at best, medium-core content (girl-girl, toys, female masturbation).
That's MY approach, anyway.