A recent podcast (TAL? Radiolab?) just discussed the retreats Google has made over time with respect to privacy and intrusive advertising. I tried to find it - someone have a link? This very much continues the theme. It is important to note how much Sergey and Larry hated advertising and the belief they held that any advertising based search engine would inherently corrupt itself.
They say what your last sentence said, so I'm guessing this is the podcast you're thinking of.