How does Bing Ads define a viewable impression for tracking view-through conversions?

Bing Ads (now part of Microsoft Advertising) defines a viewable impression as an impression of an ad that is actually seen by a user, meaning the ad is served in a way that has a chance of being visible on the screen. For tracking view-through conversions, a viewable impression is key to understanding whether an ad was likely seen by a user, even if they didn't click on it.

Here's how it works:

1. Ad Exposure and Visibility
A viewable impression is determined based on whether the ad is in a position on the user's screen where they can potentially see it.

Viewability criteria: Typically, for an ad to be considered viewable, a certain portion of the ad (such as 50% of the ad being visible on the screen for at least 1 second) must meet the standard established by the MRC (Media Rating Council) for display ads.

Display and video ads: This applies to display, banner, and video ads that are part of Microsoft's audience network or appear on search results and other placements.

2. Tracking Viewable Impressions
Tracking pixels and JavaScript tags: To track a viewable impression, Microsoft Advertising relies on tracking pixels or JavaScript tags embedded in the ad or the page where the ad is displayed. These tags measure the position of the ad on the user's screen and whether it meets the threshold for viewability.

Device considerations: The definition of a viewable impression can vary depending on the device, such as desktop or mobile. For mobile devices, ads that appear in full-screen formats, such as interstitial ads, are considered more likely to be viewable.

3. View-Through Conversion Attribution
Conversion Window: Once the ad is served and meets the viewable impression standard, if the user does not click the ad but later completes a conversion (e.g., purchase, sign-up) within the attribution window (usually up to 28 days), it is counted as a view-through conversion.

Validating Viewable Impressions: To prevent fraudulent or inaccurate impressions, Microsoft Ads ensures that only valid, viewable impressions are counted in the view-through conversion tracking. For example, if an ad was served in a location off the screen or in a manner that wasn't visible to the user, it wouldn't be counted as a viewable impression.

4. Impact on Campaign Reporting
Viewable Impressions Reporting: Advertisers can access reports on the number of viewable impressions and view-through conversions. The view-through conversion can only be attributed if the ad was in fact viewable, meaning that it met the criteria for being shown to the user.

Improved Metrics: This helps ensure that view-through conversions are based on ads that had a real chance of being seen by the target audience, leading to more reliable performance data and insights.

5. Viewability vs. Served Impressions
Served Impressions: These are simply the number of times an ad is delivered to a user, whether or not it was visible.

Viewable Impressions: In contrast, a viewable impression is an ad that has a high likelihood of being seen by a user. This distinction is important for advertisers looking to measure the real effectiveness of their ads.

In Summary:
Viewable impressions are defined as ads that are served and have a significant chance of being seen by users, with certain standards set for visibility (e.g., at least 50% of the ad must be visible on the screen for at least 1 second).

Tracking and attribution for view-through conversions rely on ensuring the ad was actually viewable, not just served, before attributing conversions to those impressions.

Advertisers can measure and optimize based on viewable impressions, ensuring that their view-through conversion data is based on valid, visible ad exposures.