Reddit readers manipulate AdSense
mashable.com
"Redditers are calling everyone to click on Rudy Giuliani's paid ads simply because they cost him money."
mashable.com
1. User clicks on ad.
2. User does something advertiser considers significant, aka a "conversion", like going to a download site or a credit card entry page.
3. Google tracks that occurence and crunches the numbers.
4. Advertiser can make decisions about what ads to run based upon how many conversions they get. Thus, if political ads never "convert" to donations, it's obvious they should be removed.