Matt Cutts of Google posted: By the way, there's another quote from me in that Red Herring story...

... "If you view ads as a necessary evil, it will color the experience." What I was trying to say is that Google doesn't view ads as a necessary evil to make money. We view showing ads as another type of search-one in which relevancy is just as important as web search. To me, ads shouldn't be this unwanted thing you have to show on the side of your site; for many searches, the ads can be just as helpful as organic search results, and we should always try to make ads a useful service to our users, not just a "necessary evil."

Read more about the importance of the relevancy factor when it comes to Adwords marketing at http://www.webpronews.com/insidesearch/insidesearch/wpn-56-20051006CuttsGoogleThinksofAdsasaTypeofSearch.html.