During the last six months, my home page: accordmarketing.com/tid/ has been ranking #3 or #4 in Google for keyphrase Internet Marketing Tips. However, in these last few days my ranking randomly changes from #3 or #4 to #64 or #65. This switch occurs several times a day. My hunch is that Google is using different servers and switching from one to the other randomly. The question then is, why am I #3 or #4 in one server and #64 or #65 in another. Interestingly enough, all the other results in the first SERP seems to remain the same, only my page changes.
My site is not new, has a PR of 5 (PR6 before the last update) and has been in Google for almost 2 years. I'm not losing any sleep over this, since most of my SE traffic comes from internal pages, but it would be interesting to understand what's going on.
Thanks,
Mario
The Internet Digest
http://www.theinternetdigest.net