[speps]

a lot of websites seem to be struggling with determining how many of their visitors are blocking ads

So they can now track people using your website? As first comment said, good luck not getting blacklisted...

[amorgan]

We don't track visitors, we're only interested if a visitor can view ads or not.

[Spivak]

Your tool is actively trying to determine what I user does with the page after it's served -- that's tracking. Yes, this behavior is commonplace in the industry but it doesn't mean you wont end up on blocklists because of it.