[lehmannro]

That search engine is still Google’s most important and profitable product, to my knowledge.

While I agree that its search engine is its most popular product it is not profitable in its own right. Google claims that "advertising revenues made up 97% of our revenues" in its Q3/2010 filings and that means advertising placed through AdSense/AdWords on other sites too:

We derive most of our additional revenues from offering display advertising management services to advertisers, ad agencies, and publishers, as well as licensing our enterprise products, search solutions, and web search technology.

-- http://investor.google.com/documents/20100930_google_10Q.htm...