Measurable Devices

The basis of our web measurement is the pixel request, and although we don’t rely on javascript support, we do require image support. Major browsers can be configured not to request images, and some mobile browsers are unable to request them. Our statistics will exclude these devices.

Breakage

Breakage refers to a page rendering that was interrupted before our measurement pixel was requested. Browsers typically execute javascript and issue image requests from the top of the page to the bottom. Although we’ve optimized our pixel delivery, we nevertheless encourage publishers to place our tag near the bottom of the page to avoid even any suspicion of slowing the page rendering down. But the larger the page, the greater the chance the user will go elsewhere before our pixel is requested. In such cases, the user will see some or all of the page content, but we will not record the event.

Blockage

A blockage is a disruption to the normal pixel request flow between the user’s browser and our servers. For example, ad blocking software might treat our tracking pixel as an ad and not allow the browser’s request to go through. A firewall might do the same thing. Or network failures could prevent the request from arriving at our data center.