My approach is from the other angle: I run an Adblocker but set it to permissive. That way if I find a really annoying site I can tap the right button and ads are blocked.
Not visiting the site anymore doesn't send the message either. Why would they assume it was obnoxious ads, rather than decreased interest in their content, competition, etc? The only way they'll know is to actually tell them.
To me that seems the fairest approach.