I found this fascinating quote today:

Google Analytics is undoubtedly the most widely used web analytics application. Emerged from and based upon the analytics-package developed by Urchin Software Corporation (which was bought by Google in April 2005), the tool has become publicly available for free under the new flagship of Google Analytics. In May 2007 the application was heavily edited, developed and released; the design was simplified and more advanced featured were added. Over years Google Analytics managed to gain on popularity because of its simplicity and many advanced features for curious site owners and professional marketers.adsensebysense.blogspot.com, Adsense Tips, Google Tips, Earning Tips

You should read the whole article.