Google's intent signal in search ads.

Search ads offer a very strong signal of intent.
Dr. Hal Varian[1]
In search ads, targeting is based on real-time declared intent.
Witness[1][2]
The consumer is literally telling you at the moment in time, tell me more about the following search.
Witness[1]
If they had a better quality search engine, they would attract more eyeballs.
MR. SCHMIDTLEIN[4]
Search advertising is one of the world's greatest business models ever created.
Mike Roszak[2]