How are you actually measuring your site's ad-block rate?

Everyone seems to cite the same “\~30% of users block ads” number. But that number can be pretty useless when you're trying to understand what is happening on your own site. Audience, device mix, geography, and even how aggressive your ad setup is can make the rate very different from the industry average. A simple way to measure it is to run a small client-side check on each pageview for something ad blockers would typically hide, such as a bait element or a request that resembles an ad resource. Log whether it loaded, tie the result to the pageview, and do it across enough traffic. You then get an estimate of your site's actual ad-block rate, instead of borrowing someone else's number. Once you have that: **Blocked pageviews × average ad revenue per pageview = rough potential revenue impact** It's only an estimate, not money you're guaranteed to recover. Some blocked visitors wouldn't have generated a monetized impression anyway. But at least you're working with a number from your own traffic rather than an industry estimate, especially one published by a vendor that also sells solutions for ad-blocked traffic. Curious how other publishers are measuring this today. Are you using your own detection script, an analytics tool, or just estimating from the industry numbers? Disclosure: I run Widgetail. I wrote a longer version of this for our blog: BLOG