iamlost - 3:38 am on May 6, 2007 (gmt 0)

Note: my experience with rotating content is on content/information sites.

Long ago (Before Google :)) I started rotating in both 'new' and 'popular' title-description-link snippets on home pages (in those days home pages were major entry points) and found that traffic volume to those 'snippet linked' pages had a direct correlation to exposure rate.

I then began rotating the content on category (directory index) pages (not hiding anything, simply changing the order on the page) and found that (much like SE query results) the higher category descriptions siphoned off the bulk of the traffic. It allowed me to even out traffic flow somewhat and raised the popularity of less popular content (sort of like B&M stores forcing you to walk by all the other stuff to get to why you went in the first place generating impulse sales).

My home page new/popular insets change daily. My category pages change order weekly (each at different day/time). As said most of this grew up before and with Google. Never had a problem (knocking my head on wall).

I have no idea whether the change in display order without change in content is 'good' for ranking in and of itself. I do believe that it acts to spread out traffic levels somewhat which may have a 'good' effect on the ranking of what would otherwise be poorly trafficked pages.