Favor viewability over fill rate

By default, all Brid outstream ad units have this feature disabled.

If you leave this option unchecked, the Brid ad unit will initiate your ad waterfall as soon as possible, typically upon page load. This prompt action ensures that the ad content intended for the outstream unit gets prepared in advance. Consequently, when a site user navigates to the section where the outstream unit should appear, your ad content will ideally be ready for playback.

Since the Brid ad unit remains hidden from the user's view (as is the expected initial state of an outstream ad unit), the Brid player must pause your ad content in the background, out of sight. Ad providers may interpret this as non-viewable ad content, even though playback has not yet begun.

If viewability is a concern for your ad inventory, you may want to enable this option. When enabled, the Brid outstream unit will still commence your ad waterfall promptly but slightly later than when left unchecked. With this option enabled, your ad waterfall starts when a site user navigates to the location where the outstream unit is supposed to appear. Depending on the size of your ad tag waterfall, it may take some time before your ad displays in the unit.

TL;DR:

Consider enabling this option if your ad tags encounter viewability issues.