Viewability

When is viewability tracked?

Viewability is tracked through a JavaScript deployed at the time of the rendering of the ad.

When is an ad impression deemed to be inview / inscreen?

An ad impression is inscreen when

• either more than 50% of the ad surface is viewable to the user for at least one second.
• or more than 30% of the ad surface of an ad of at least 242 500 pixels is viewable to the user for at least one second.

What rate of ad impressions are viewability tracked for?

We attempt to track 100%.

With what frequency is viewability tracked?

We track viewability with a frequency of 1000ms.

What metrics related to viewability are presented?

We currently present impressions, measured rate (%) and inscreen rate (%).

Is there circumstances when viewability is not tracked?

We do not attempt to track viewability for

• ads marked as expandable
• ads in cross domain iframes

Do all integrated seller platforms allow viewability tracking?

This varies between SSPs.

SSP	Measured Rate
AppNexus, DoubleClick, Fyber	Low < 10%
Admeta, Improve Digital	Medium 20 - 80%
Rubicon, Pubmatic, Adtech, Switch Concepts	High > 80%