[Semaphor]

I’m talking about actual, legit bots. Facebook, Instagram, all those search engine crawlers. Those follow all kinds of links, including ads, and then go and annoy us and the advertisers by counting as "fake traffic".

Google is/was (we wrote our own simplified adserver, only using AdManager for the agencies that require it, so I’m not sure how much things changed in the last two years) not only happy letting those through, they even send their own, it was so bad that we redirected all links through our site where we filtered all Google IP ranges (because, of course, whatever they used did not have a proper bot UA) that we could find to block them and stop sending 1000s of fake visits to the advertiser every day.

[Multicomp]

I wonder if these bots would respect robots.txt files for the ads?

[Semaphor]

Well, you’d have to get Google to host those robots.txt as the ads are running iframed on their servers ;)