Webmeister - 7:08 pm on Jun 26, 2010 (gmt 0)
Thanks for the input Tedster - it helps me brainstorm this issue.
Let me give you another example of a recent test I did. I purchase a domain that had a PR3. It ranked on Google at #9 for a popular phrase that brings in some good AdSense traffic. I changed the entire website - template, links, page content, etc. and it didn't affect its Google ranking at all. However, I made another change that dropped it completely out of Google: used 301 redirects to point the non-www version of the site to the www version. Within 10 days, Google dropped it completely. Three weeks later, I took the 301s down and allowed the non-www version to be active - and within a week, it popped back up on Google at #7 for its keyword phrase.