Ad Manager transition to downloaded impressions

Google Ad Manager is changing how ad impressions are counted

On October 2, 2017, Google Ad Manager changed the way ad impressions are counted to align with industry standards.

Served impressions and downloaded impressions

Until recently, the Interactive Advertising Bureau (IAB) stated that ad impressions can be counted as soon as they are sent to a publisher by the ad server. The industry, however, has changed significantly since this standard was created and the Media Rating Council (MRC), in conjunction with the IAB, is taking steps to transition from counting impressions on ad server decision (i.e., ad is served) to counting impressions on download (i.e., ad begins to load on a page).

  • Served impression: An impression counted when an ad is sent, or "served," to a publisher by Ad Manager. The ad creative may or may not be rendered, downloaded in the user’s device, or viewed by the user.
  • Downloaded impression: An impression counted only after the initiation of ad retrieval by the publisher. The ad creative is downloaded in the user's device and has begun to load. A separate viewability measurement will determine if the user has viewed the creative.
With this change, the "Ad server impressions" and "Ad server downloaded Impressions" metrics now count purely on downloaded for all inventory. Previously only ad types that use delayed impressions, such as video or interstitials were counted with this methodology.

Summary and timeline of changes

Timeline Summary of change
February 6, 2017 New metric in Ad Manager reporting: Ad server downloaded impressions
Ad Manager introduced the Ad server downloaded impressions metric to provide visibility into any discrepancy between today’s definition of "impressions" and downloaded impressions for Ad Manager reservation traffic.
March 2, 2017 Updated basis for "Ad server Active View eligible impressions" metric
The "Ad server Active View eligible impressions" metric uses downloaded impressions as the impression basis, instead of served impressions. This change better aligns Active View with how third-party providers measure viewability. This methodology change is not retroactive and only affects reported data on and after March 2nd. Learn more
May 15, 2017

Counting methodology updated for Ad Exchange backfill and Open Bidding impressions
Ad Manager impressions that filled by Ad Exchange, where the buyer is Google Ads, and Open Bidding use the downloaded impressions methodology.

This change only impacts inventory bought by Google's Ads because inventory bought by third-party bidders already uses the downloaded impressions counting methodology. Ad Manager customers filling impressions via Ad Exchange can expect to see a nominal drop in Ad Exchange impressions that is counteracted by a proportional increase in CPMs. The result of this change will be revenue neutral to our publishers.

August 2017

Ad Manager forecasts started using downloaded methodology for projections
Forecasts will begin using historical downloaded impressions as the basis for impression volume projections for dates following October 1, 2017.

For example, if you forecast today for a line item that will run September 15 - October 15, the forecast for the first half of the delivery period (September 15-30) will use the served methodology, but the second half of the delivery period (October 1-15) will use the new downloaded methodology. Similarly, a forecast for a line item that will run October 1-31 will use the downloaded methodology entirely.

October 2, 2017

Counting methodology updated for remaining Ad Manager impressions
Ad Manager reservation impressions began counting and billing impressions on download.

If your network uses Ad Manager Data Transfer, impression files will only include downloaded impressions. New files will soon be available for requests and code serves.

Tagless Requests are most often affected by this change

If you use Tagless Requests to serve ads through Ad Manager, you might need to take action to avoid interruptions to impression counting. Tagless Requests are also the most common reason for report discrepancies between served and downloaded impressions.

Simple image requests and tracking pixels are not supported

Tagless Requests that use gampad/ad in HTML image tags (<img>) are not supported for downloaded impression counting. Since these requests do not support the use of JavaScript tracking code, only a code serve can be counted. This might cause a discrepancy in your reporting. To report on these ads, use the "Total code served count" metric in Ad Manager reporting.

HTML image tags trafficked in Ad Manager as creatives using the custom or third-party creative type are not affected and will continue to count impressions using the downloaded methodology when served through compliant ad tags.

Ad Manager creative macros or custom HTTP header handling is required

To count downloaded impressions for Tagless Requests that use gampad/adx, you need to implement custom handling either through the creative with the viewed impressions macro, or with a custom integration that uses HTTP response header information to tell Ad Manager when to record a downloaded impression. Learn more about how to record downloaded impressions with Tagless Requests.

See whether Tagless Requests are causing a discrepancy in your network

  1. Sign in to Google Ad Manager.
  2. Click Reports and then Queries.
  3. Click New query.
  4. Create a Historical query, covering dates after February 1, 2017:
  5. Click Run.
  6. Compare the Ad server impressions and Ad server downloaded impressions metric totals for rows containing the "GPT Simple-URL" request type.

    If the ratio between them is lower than 90%, or significantly lower than your network's overall average, your Tagless Requests are likely not set up correctly. Follow Tagless Request best practices to resolve the issue.

How does this affect Data Transfer reports?

If your network uses Ad Manager Data Transfer, impression files only include downloaded impressions starting October 2, 2017. New files will soon be available for requests and code serves. Watch the release notes for more details.

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