Floodlight only records conversions for users who have previously seen or clicked on a Campaign Manager 360 ad within a period of time you specify (called a lookback window). When a user loads a web page containing Floodlight tags, the ad server accesses the user's cookies or device ID. Campaign Manager 360 then runs an overnight process for each Floodlight impression, checking to see whether there is a match for any previous impressions or clicks on Campaign Manager 360 ads within the lookback window. If no match for the cookies or device ID is found, the activity record is discarded.
The lookback window values start at 0 days. That is, a window of 0 counts events within 24 hours, a window of 1 counts events within 48 hours, a window of 2 counts events within 72 hours, and so on.
Note that for app tracking via Firebase and 3P SDKs, the lookback window values start at 1 day. A window of 1 counts events within 24 hours, a window of 2 counts events within 48 hours, a window of 3 counts events within 72 hours, and so on.
The lookback window for any given user impression or click is based on the value set for the placement where it took place. If a user has clicked or viewed ads in multiple placements, Campaign Manager 360 uses the most recent click that falls within the lookback window of the placement where the ad was served. If no click is available, the most recent impression is used.
Bob's Widgets is running a campaign across Placement A and Placement B. A user sees the ad called "Love the Lemur" in Placement A. A few minutes later, the user sees the ad called "Pet the Panda" in Placement B and decides to click, because pandas are adorable. Ten days later, the user visits the advertiser's site and makes a purchase, triggering a Floodlight impression for a sales activity.
Placement A's lookback window for impressions is 14 days. Placement B's lookback windows for clicks is 5 days, so the click can't be used for calculating Floodlight data. However, Placement B's lookback window for impressions is 14 days. As such, Floodlight records the impression as a sales activity and associates it with the impression of the ad "Pet the Panda" served to Placement B.
Note that for publisher tags, lookback windows for the advertiser (not the placement) are used. To avoid discrepancies, we recommend you set lookback windows at the advertiser level and use default values for placements.
If you share your Floodlight configuration across Campaign Manager 360 and Search Ads 360 and update your lookback window in Campaign Manager 360, the update will propagate to Search Ads 360 and will be used going forward.
Lookback window settings
Lookback windows can be set for an account, advertisers, campaigns, placements, and sites. The maximum lookback window is 90 days.
Lookback windows without overrides
Lookback windows are simplest if you don't set any overrides at the campaign or placement levels. An override is a lookback window setting that supercedes the inherited value.
If you don't use overrides, you only need to set lookback windows at the account and advertiser levels. Advertiser values are used in placements. If you change an advertiser's lookback windows, the changes are reflected in placements.Learn about overrides
Lookback window overrides can be set for placements and campaigns. An override value can't be greater than the value set for the advertiser. For example, if the lookback window for clicks for the advertiser is 10 days, you can create a placement override of 7 days, but not a placement override of 14 days.
When you set an override in a placement, the placement's value is saved, regardless of changes at any other level. There's no way to make batch changes to placement lookback windows that use overrides.
If you remove the overrides from the placement, it will revert to inheriting the advertiser's lookback windows. Subsequent changes to the advertiser's values will be inherited by the placement.
Campaign overrides set the lookback windows for new placements that you create manually in Campaign Manager 360.
When you create a new placement, campaign override values set the default values as overrides. This means subsequent changes to campaign values won't be inherited by existing placements.
Site lookback windows
You can set lookback windows for sites. If no campaign override is set, the site lookback window is shown as the value when you're creating a new placement. To use the site value in the placement, you must enable an override. Otherwise, when you save the placement, it will revert to inheriting the lookback window from the advertiser.
Because site lookback windows are difficult to apply, it's generally best not to set lookback windows at the site level.
All inheritance rules apply separately for each lookback window. For example, a placement could have an override set for its lookback window for clicks, but not for impressions or Rich Media events. Similarly, you can set a value for some, but not all, types at the site level. You can also set overrides for some, but not all, types at the campaign level.
Lookback windows and publisher tags
Floodlight uses advertiser (not placement) lookback windows to decide whether to serve publisher tags. As such, if a placement has lookback window overrides, you might serve the publisher tags more often than you count a conversion.
For example, the lookback window for clicks is 10 days at the advertiser level, but 3 days at the placement level. A user clicks on an ad on Site A, then visits a Floodlight-tagged webpage 5 days later. No conversion is counted because it's outside the placement's lookback window. The publisher tags for Site A are served based on the advertiser's lookback window.
If you use publisher tags to serve tracking tags for your sites, it could lead to a discrepancy over the number of conversions a site has provided. To avoid this problem, avoid using overrides in your placement lookback windows.
Effects of changing placement lookback windows
You can change lookback windows to make them longer or shorter. The changes are immediate and only applied to any new Floodlight impressions. The number of conversions counted before the change is not effected.
Example: Lengthening lookback windows
You have a placement with an impression lookback window of 5 days. Six days ago, a user saw one of your ads. Today that user visited your Floodlight-enabled web page. A Floodlight impression is recorded, but it's not a conversion because it's outside the lookback window.
Subsequently, you change the impression lookback window to 10 days. This change has no effect on the Floodlight impression that already occurred. The next day, the user returns to your web page, triggering another Floodlight impression. It has now been seven days since the user saw your ad. Since the impression lookback window is now 10 days, a conversion is counted.
Example: Shortening lookback windows
You have a placement with a lookback window of 10 days for impressions. Four days ago, a user saw your ad. Today that user visited your Floodlight-enabled web page, and a conversion was counted.
Subsequently, you change the impression lookback window to 3 days. This change has no effect on the conversion that was previously counted. However, when the user returns to your web page the next day, no conversion is counted, because the lookback window is now shorter.