I know many affiliates worry about search engine duplicate content penalties, especially regarding datafeeds. However there are several other duplicate content issues affiliates, merchants and all webmasters should be aware of. Mike McDonald reports from SES on WebProNews:

“Plenty of websites try to pull tricks that will move them up in the rankings. People like Matt Cutts take gleeful delight in exposing the likes of BMW and Ricoh and booting them out of Google’s index. Anyone thinking Google or Yahoo wouldn’t ban their site should think again.

Presenters at the SES 2006 New York session, Duplicate Content Issues, discussed the dangers of duplicate content. It comes in many forms, like multiple domains for the same homepage content; multiple links to several domains for one site; and “doorway” pages, according to Anne Kennedy, managing partner at Beyond Ink. “

Lots of great tips and pointers here. Also in this article it’s reported that Matt Cutts said Google’s “Bigdaddy” datacenter update is rolling out every 7 to 10 days and it should be done in the next 6 weeks. SES NY Duplicate Content Jeopardizes Your Site