Great interview at the Wired site with Google CEO Eric Schmidt. (Click here to read.) When asked about what kind of business Google is, here's how Schmidt responded:
Think of it first as an advertising system. Then as an end-user system - Google Apps. A third way to think of Google is as a giant supercomputer. And a fourth way is to think of it as a social phenomenon involving the company, the people, the brand, the mission, the values - all that kind of stuff.
As I wrote in Googlepedia, Goolgle is first and foremost an advertising company. Note how the word "search" doesn't appear anywhere in Schmidt's response.