I'm new to Adsense -got into it by "accident" when a client abandoned a domain that I had developed for him - so I took it over and added some monetizing. - Anyway...
I was also wondering if "this system" could be used "to tweak" Google's content network PPC pricing algo/smartpricing". If a well structured bot could affect G's PPC, by artificially lowering/raising bids on the content network, then I imagine that ability could be financially exploited.
I think that Webworks has spotted one of the many components that make up this issue.
When I added an Adsense advert code to a page, I immediately noticed that each time I browsed to the page, there was an immediate "retrieval" of the same page - by a Google related spider/bot. (Think it even had "AdSense" in its name)
And if I remember correctly, when I added a second advert to the page, every retrieval triggered 2 "visits".
So, being an Adsense newbie, I thought that that was the way it should be and carried on.
Did not worry about my stats being skewed because my site engine's statistics module was identifying the visits as being from a spider/bot and the visits were not skewing my "human visitor statistics".
But as I mentioned earlier, this is only one component that makes up this issue.
The second component is all the bounce visits.
Could (probably has) become very serious and is probably behind so many guys being thrown off of Adsense recently.
I am sure that everyone has at some time or other been asked by Google to verify your humanity because they have detected that you may in fact be an automated process.
So you type in the captcha and off you go.
Now implementing this on a site may sound simple but there are a whole bunch of things to consider.
1) You do not want to screw around with legitimate spiders/bots that you want to visit your site.
2) You do not want to screw around with legitimate human visitors unnecessarily.
(I hear that Google will not be supporting IE 8 and lower from sometime soon - AT LAST!)
3) You want to detect and store as much information as possible, ESPECIALLY on the bounces, so that you have it available for submission to ISP's, Google (maybe inform them of the nonsense going on) or possibly the legal team of a class action should things need to be taken that far.
4) You may want to make the whole process intelligent and detect if more than 1 bounce comes from a specific ip in the last X seconds and if there has been, ban that ip for 24 hours.
5) There are also certain pages that the "kiddie-hackers" always test for - wordpress admin pages, drupal admin pages, phpbb posting pages and all the rest - so, if you build up a list of "kiddie-hacker" pages that are not on your site (if you are NOT running a wordpress site, anyone who probes for the wordpress admin page is only up to no good) and if they are looking for one of the pages in the list, ban the ip for 24 hours right there and then.
Hows this for an idea?
When an illegal probe is detected, fire of an email immediately to the ISP giving them all the details.
They can then "take up the matter" with their client and you have proof of what has happened.
Imagine some little idiot sitting at his pc up to no good and the phone rings - the ISP phones up and tells him to stop his crap - should make an impression!
Draconian? Definitely - but we are fighting for our lives here.