Content Rotation is the technique by which content publishers
(TV studios, magazine publishers, websites etc.,) recycle previously
published contents, to reach audiences missed during an earlier broadcast.
It is an effective way for content producers to get ROI (Return of
Investment) on popular content that they own. In the television world it
is called the re-runs, on MSN, Seven Stocks to Watch, and in Cosmopolitan it is called How to have Great Sex. 
The idea is same -- great content is extremely hard to produce, so sell popular old content over and over again.
A simple content rotation scheme just involves picking a random story or picture and displaying it. Picture intensive sites like Corbis do this; every time you refresh the page, you see a new picture. An
arbitrarily generated number determines which picture to display. Our Kaleidoscope
is implemented this way. It is an inexpensive way to amuse visitors for a long time.
• Amateur Webmaster: Content Rotation for Websites
• The Amateur Webmaster
• Check out the Content Rotator for this site. Keep refreshing till you find something interesting.
