Microsoft launched IE 7 then asked both  Yahoo and Google to promote it.

The Reality is that neither Yahoo nor Google noticed that Microsoft has sent them a standard format of webpages, content and images.

Yahoo promoting IE 7 - Google newly updated promoting IE7
Yahoo & Google ended up using same webpage to promote IE 7 ( latest Internet explorer )

Google upgraded their IE 7 ads page and Matt Cutts apologizes for that misunderstanding or misleading tactics by Microsoft. 
Image by Google Blogoscoped