Without search, AdWords would be worthless.
When you use Google, or any other ad-supported site, you should know that you are the product, not the customer. The site is getting paid by its advertisers for exposing you to the advertisers' pitches. Of course, you won't pay attention unless the site is useful, fun, or interesting. Thus, making sure it's the above is the site's owner's mission. This phenomenon is basic to media and far predates the internet.
In Google's case, the attraction is fast, accurate search. Google built it, and they came. And the advertisers fork over big time for access to that audience.
AdWords is used by people that wish to put advertising on their own website, whether google was used to get there or not. Google dominates in this kind of service .