Lookback Window

What is Lookback Window?

A lookback window is a predefined time period during which a user interaction, such as a click or an impression, can be credited as the source of a subsequent install or conversion. If a conversion occurs within this window, the earlier touchpoint receives attribution credit. If the conversion happens after the window expires, that touchpoint is excluded from attribution.

How it works

When a user clicks on or views an ad, the mobile measurement partner (MMP) records a timestamp for that interaction. The lookback window starts from that timestamp and defines the maximum number of days during which a downstream conversion can be linked back to the original touchpoint.

Click-Based Lookback Windows

Click-based lookback windows track the period between a user clicking an ad and completing an install or in-app event. Common durations are 7 days and 30 days, with shorter windows typically applied to lower-intent formats such as banner ads and longer windows applied to higher-engagement formats such as playable ads or rich media units.

Impression-Based Lookback Windows

Impression-based lookback windows, used in view-through attribution (VTA), track whether a user saw an ad without clicking it and later converted. These windows are typically much shorter, often 24 hours, because the signal from a passive impression is weaker than from an active click.

How Attribution Is Determined

When a conversion is recorded, the MMP looks back through the window period to find qualifying interactions. If a qualifying click or impression exists within the window, attribution is assigned according to the configured attribution model. If no qualifying interaction exists within the window, the install is recorded as organic.

In Airbridge, the lookback window applies specifically to app installs, while the attribution window applies to subsequent in-app events. This distinction ensures that post-install activity is measured against its own appropriate timeframe rather than the install-focused window.

Why it matters

Setting an appropriate lookback window directly determines which ad interactions receive credit for driving installs and conversions. A window that is too short causes genuine ad-driven installs to be misclassified as organic, understating campaign performance and skewing budget decisions. A window that is too long attributes conversions to interactions that had minimal influence on user behavior, overstating campaign effectiveness and misallocating spend.

Lookback windows also affect fraud exposure. Longer windows create more opportunity for click spam and click injection schemes to insert fraudulent touchpoints before a legitimate install occurs, making window length a meaningful fraud-mitigation lever as well as a measurement one.

For advertisers running multi-channel campaigns, consistent lookback window settings across all channels and networks are essential for fair comparison of performance. Mismatched windows across partners make channel-level benchmarking unreliable.

How to Set Up a Lookback Window

Step 1: Map the Customer Journey

Review historical data to understand how long users typically take from first ad exposure to install. If most installs happen within two days of a click, a 7-day window captures the vast majority of attributed installs without unnecessary extension. If your product has a longer consideration cycle, a 14-day or 30-day window may be appropriate.

Step 2: Match Window Length to Ad Format

Align your lookback window with the nature of the ad format. Transient formats such as banner ads warrant shorter windows, typically 7 days, because a brief exposure is unlikely to influence a user weeks later. High-engagement formats such as playable ads or rewarded video can justify longer windows, such as 21 or 30 days, to capture users who engaged deeply but converted later.

Step 3: Set Separate Windows for Clicks and Impressions

Configure distinct windows for click-through attribution and view-through attribution. Impression-based windows should generally be shorter than click-based windows to reflect the weaker causal signal from a passive view.

Step 4: Align Settings Across All Partners

Ensure that the lookback windows configured in your MMP match the windows set by each ad network or self-attributing network (SAN). Mismatches create attribution discrepancies where the network claims credit for conversions that fall outside the MMP window, or vice versa.

Step 5: Monitor and Adjust

Review attribution data periodically to identify whether the configured window length aligns with observed conversion timing. If a meaningful share of attributed installs clusters near the end of the window, consider whether that window is capturing genuine intent or accumulating noise. Airbridge provides campaign-level reporting that allows marketers to analyze install timing relative to click timestamps, making it straightforward to evaluate whether the configured window is correctly calibrated.

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