Found at DigitalPoint Forums a very interesting, 15 minute, video tutorial of a theory on how Google does not arbitrarily pay publishers. The video presentation only works on IE for PC and is viewable at http://www.articlebot.com/tutorials/adstochastics.html.
Basically, he shows how there is a pattern to how one's average price per click is over time. He compares it directly to how stocks are estimated to rise and fall. The statistics is named Stochastics, something I know very little about, but it seems from his presentation that if you were to apply the "Stochastic Oscillator" (i.e. "a momentum indicator that shows the location of the current close relative to the high/low range over a set number of periods. Closing levels that are consistently near the top of the range indicate accumulation (buying pressure) and those near the bottom of the range indicate distribution (selling pressure).") to your AdSense figures you can;
(1) See that there is a clear pattern to how Google pays you per click; it is not arbitrary. (2) You can use this data to know when to put less focus on your AdSense ads. For example, if you know your PPC will be at its lowest for the next X days, you can switch over to YPN ads or something else. If you know your PPC will rise, you can direct more traffic to those pages. Informed decisions through statistics. :)
Very interesting presentation, in my opinion.
Forum discussion at DigitalPoint Forums.