[majormajor]

I haven't worked in the adtech space in years, but third party counts were a thing from the advertiser side for basically this reason. Nobody trusted the network to say "yep, we showed your ad this many times, pay up."

I'm not sure how fraud detection works there, though. Maybe there's third party counting that includes third party fraud checks? Back then, at least, the incentive to spot fraud wasn't high - advertisers didn't want to admit to their stakeholders that they were wasting their money any more than the adtech network wanted to admit it to the advertiser.

Your scenario is also interesting from the publisher side - especially on non-web properties where a musician doesn't even have the ability to embed their own JS in their song to collect their own counts or use someone else's playcount counting library...