About Celtra’s Impression Metrics

Celtra’s reporting contains 3 different impression metrics:

• Requested Impressions

• Loaded Impressions

• Rendered Impressions

We track these in order to provide the most granular level of impression reporting and to accommodate DSPs/SSPs’ ever-changing counting methodology.

We commonly see exchanges reporting some version of shown, rendered, or viewable impressions. Different impression counting methodology doesn’t necessarily mean there’s a real discrepancy, but a difference in standards for reporting. Below are some examples of these.

The requested impressions metric is the number of ad requests received by Celtra. Celtra receives a request when an ad-server executes a Celtra tag and sends a request to ads.celtra.com.

The load rate metric is calculated as the ratio of loaded impressions to requested impressions.

For an impression to be considered loaded, a creative must meet the following criteria:

• Be loaded and displayable on a user’s device.

• The Base and the first page of the banner unit have loaded.

• The SDK has initialized.

Take, for example, an application that has precached/preloaded the creative waiting to be rendered. The creative may not be in the user’s viewport, but it has loaded, so Celtra will count this as a loaded impression.

The Rendered impressions metric represents the number of Loaded impressions in which the creative content appeared and started playing (if it included animations or video). It is calculated differently depending on which environment a creative is served in.

We calculate it using the below methodology:

• For display formats, Rendered impressions are counted once any portion of the creative (at least 1px or more) is in view for any amount of time as detectable within the current environment - this is a more generous metic than most viewability metrics which typically follow the IAB Viewable definition of 50% of the creative in view for at least 1 continuous second.

• For video-first formats, this is counted when the playback began. Rendered impression is a necessary condition for any user-initiated actions (such as engagements or clicks).

• In MRAID environments, a rendered impression is counted when the mraid.isViewable() method returns a ‘true’ value.

• In web environments, a rendered impression is counted when at least 1px of the creative is in view for any amount of time as detectable within the current environment.

We don’t offer viewable impression metrics like the IAB Viewable impression but rather we encourage our clients to use a trusted measurement vendor, such as MOAT, IAS, DoubleVerify, or ComScore.

The primary differences between rendered and viewability is how these metrics are defined. A creative is typically considered "viewable" (based on the IAB criteria) when at least 50% of it is in view for at least 2 continuous seconds.

Rendered rate is the ratio of Rendered impressions to Loaded impressions.

Rendered Impressions is the number of Loaded impressions in which the creative content appeared (best-effort, optimistic) and started playing (if animated or video). It is a necessary condition for any user-initiated actions (such as engagements or clicks).

• For display ad formats, this is counted when the first screen of the first unit (excluding the Base, Loading and change orientation screens) is displayed.

• For video-first formats, this is counted when the playback began.

Rendered & Viewability Definitions

Keep in mind that Rendered Impressions are not the same as Viewability metrics like IAB Viewable. Also, a metric named Rendered may not be equivalent to the same name metric between different vendors, since they measure Viewability differently.