Google’s Chief Economist, Hal Varian, spoke during a Google Tech Talk on October 22, 2012, and he shared some interesting information about what you see every time you use Google, as Barry Schwartz reported for Search Engine Land.
“Any time you access Google, you probably are in a dozen or more experiments.” Google is always working to improve and refine how they record data. Google releases about 500 updates to search per year, and about another 500 on the ad side. To establish what changes are needed and what works best, they run these experiments, which come to about 5,000 different experiments in a year,
The video of the entire talk is below, and the relevant information starts around the 26 minute mark.