On the advertiser side of Google's services, I have a refund for "invalid activity" on almost every monthly statement going back nearly a decade.
> You received a credit because we found invalid activity on your ads. What is it: Invalid activity refers to clicks and impressions that we suspect aren't the result of genuine customer interest. We don't charge you for invalid activity on your ads. Example: Invalid activity includes clicks and impressions performed by automated tools, as well as accidental clicks – for instance, if someone double clicks your ad.
