From this Infoworld article:
Microsoft (Profile, Products, Articles) Corp. will share a part of its advertising revenues from its search engine with users, the company’s chairman Bill Gates said in a panel discussion on an Indian television channel.
Gates said that search engines like Google (Profile, Products, Articles) Inc. get their revenues from advertising because people use these search engines. “Google’s business model is not based on free software,” Gates said. “Their business model is based on advertisements from which they make a lot of money.”
But they don’t share these advertising revenues with the end users who help them get the revenue, Gates said. “Google keeps all of the money with itself,” he added.
(Through its AdSense program, Google does share advertising revenue with Web site publishers who carry ads that Google sells to advertisers.)
In its bid to share revenues with users, Microsoft may give free software or even cash to users, said Gates, who did not discuss further details.