Much harder to get right than you'd think and if you're a big site it's worse: the block lists will be updated to "whitelist" your test ad.

It's difficult for publishers to even accurately measure what impact ad blocking is having on their business.

I use AB Edge. I've visited Reddit, they posted a "we notice you use an ad blocker, if you like us, please think about whitelisting us." They could have just refused to serve the content. Either way would have been acceptable; it's my browser and I control what I see, it's their content and they control where it goes.

In that case I whitelisted Reddit. Nothing on Reddit remote-controlled my machine, it just initiated a brief "conversation."