Ad Manager transition to downloaded impressions
On October 2, 2017, Google Ad Manager changed the way ad impressions are counted to align with industry standards.
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.
See a visual guide to impression counting
- A publisher sends a request to Google Ad Manager for an ad.
- Ad Manager assembles a list of line items that match the request's targeting.
- Ad Manager selects the best ad to serve and sends the creative back to the publisher.
- The publisher downloads Ad Manager's response to render the creative code, retrieving images or video assets.
- Starting October 2, 2017, Ad Manager counts an impression at this step in the process. An impression is counted when the ad response is loaded, even if the ad content isn't fully downloaded. Previous to this change, Ad Manager counted an impression at step 3.
- Starting October 3, 2017, Ad Exchange and Exchange Bidding mobile app impressions served by Ad Manager are counted when the ad content has begun to load and at least some part of it is displayed within the user's view.
- The user views the ad, meeting the creative's viewability standard.
|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 Exchange Bidding impressions
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.
Ad Manager forecasts started using downloaded methodology for projections
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
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.
If you use Simple URL tags to serve ads through Ad Manager, you might need to take action to avoid interruptions to impression counting. Simple URL tags are also the most common reason for report discrepancies between served and downloaded impressions.
Simple image requests and tracking pixels are not supported
Simple URL tags that use
gampad/ad in HTML image tags (
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 Simple URL tags 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 Simple URL tags.
See whether Simple URL tags are causing a discrepancy in your network
- Sign in to Google Ad Manager.
- Click Reports Queries.
- Click New query.
- Create a Historical query, covering dates after February 1, 2017:
- Click Run.
- 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 Simple URL tags are likely not set up correctly. Follow Simple URL 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.