they realize that there's going to be some people out there that click like that. it happens on almost a daily basis on my site. i receive hundreds of clicks per day by hundreds of unique ips so the chances of someone clicking on multiple ads is going to go up. i've contacted G and they said that i don't need to report every single occasion of this happening.
i think you are right. if you are honest publisher of adsense since long time or even sorter time then google knows that someone clicks on your ads. so they donot pay you for that. if someone clicks again and again and google bans then i think no account in adsense will continue more than 1 month. because evey one clicks on the ads of his opponent. so be honest google will never bann you
Yeah, the combination by changing the ads format, placement and color would be nice to try to get high CTR.