Ref: http://www.mattcutts.com/blog/caffeine-update/ As stated in Matt Cutt's blog earlier about Caffeine update is going to take effect within weeks to months from 10th August 2009. He also mentioned that not many would see the difference of it's effect. But, I noticed a lot of difference with a simple set of keywords. Some low positioned sites ranked so high in new caffeine update site. Although, I don't check the content of this sites to compare the relevancy, but I notice fairly about 30% difference from current google.com and caffeine update search engine. Have you check the differences in search results? What is the percentage of changes from current google and caffeine updated search engine? Check the changes from your site and share the difference between these two search engines. Google: http://google.com Caffeine testing search engine: http://www2.sandbox.google.com