Some of my highest clickthrough rates and eCPMs come from articles and sections of my site that have prodigious amounts of information. If your site is an authority for a topic, you're more likely to attract and keep users who are seriously interested in the products or services that are offered by advertisers (and by affiliate partners, if your topic lends itself to affiliate links).
The strategy of capturing users via search and sending them away almost immediately via AdSense clicks has several obvious weaknesses:
1) It requires a constant stream of new search referrals, and it makes the site extremely vulnerable to changes in search algorithms.
2) Because users are unlikely to come back to a site with little information, the site loses other opportunities to profit during the user's personal research and buying cycle. (If you don't understand why this is important, search Google for information on DoubleClick's "research before the purchase" study.)
3) Clicks from sites with little information aren't likely to convert well. (In the travel sector, for example, the clickers are more likely to be "lookers" than "bookers.") This could lead to greater smart-pricing discounts for advertisers and less money for the publisher.
4) Finally--and most important--users who aren't satisfied with the information on a site don't have to click on ads: they can just as easily use the back button to return to the search engine. (Unless, of course, you've been stupid enough to disable the user's back button.)