Rumbas - 2:45 pm on Sep 23, 2010 (gmt 0)
Tedster, I've seen this too on one of the most trafficked sites I'm involved with.
It's been going on for years and traffic is a flat line. Pretty high volume for our neck of the woods (3-4K a day).
However NOTHING will move this site. Tons of new links coming in every month due to a heavy load of new content being developed daily - no dice, has been sitting firmly at the same level for ages.
I don't believe it's related to page/server speed as we moved recently from a slow host to a new lightning fast server.
It's a Wordpress site, it has Adsense, it has GA and a GWC account installed.
Personally I think Adsense and Analytics might have something to do with this, but of course I'm not sure.