How many Web sites get loads and loads of PR (and attract extra hits) just for making a change on the home page? Google does it all the time, every time it changes its logo (also known as its "Google Doodle"). Today's case in point: Google's logo celebrating Galileo's telescope (above).
Not only does Google get a nice surge of positive publicity, it also educates anybody who clicks on the logo. Today's telescope logo led me to a results listing of 2.36 million hits about Galileo and his invention. Clicking on news about "Google Doodle" turned up 81 hits, some about today's Galileo logo, some about upcoming contests, and some about previous logo changes.
If Google's ROI in Google Doodles is measured in number of additional searches, my guess is that the company enjoys an extraordinary return every time it loads a new logo.
BTW, when I entered "Bing" in the Google search box, the top result was a sponsored link to . . . Bing.com. I clicked.