More than often, they cause the page to jump down, or hide content, that's when I block them.
Of course, because of some websites doing this, I actively block ads on all websites.
But like I said, they have to be there on page load, not do this weird thing that causes content to jump around.
Don't bother to track ad clicks (because they can be gamed) and don't sell ads based on clicks (because then they WILL be gamed) and the problem vanishes. Click fraud is a problem the advertising industry created for itself, and other advertising mediums without invasive user-tracking seem to get on just fine without it.
Base payment scales on impartial ratings of website popularity.
I'm harshly anti-ads (for a swathe of reasons), but the problems of ad-fraud is an internet-unique problem. Advertising campaigns on TV, Radio, and paper mediums didn't track views (clicks didn't exist, my gosh!). An assumed value was given to the advertising based on the popularity of the particular TV show, radio program, magazine type, etc. AND the ads were generally targeted to the audience of the medium.
The advertising industry had this problem solved before it even became a problem. They wanted more, and are whinging about people blocking their methods to gain this 'more'.
Just don't create online dossiers on individuals, don't provide yet another vector for malware, don't invade our spaces with uninvited sound, don't slow down the sites I've chosen to view, don't waste my bandwidth.
Did that not go anywhere?
Bonus points for being SVGs and thereby saving my bandwidth and looking nice across all resolutions.