Google Patents Adaptive Technique

Google has patented a technique " ... to decipher which page regions and topics the viewer is interested in based on the viewer's behavior after he's arrived at the page ... ". Normally the choice and placement of ads are done before the user arrives at a page. This looks quite broad on a quick scan, but the implications could be interesting. It comes to mind that with all their data, it would easy to set up a simulation to test all sorts of alternative model constructs. Such predictive models could then be used to optimize and sell given ad arrangements. A potentially powerful idea. Also in Slashdot.