Attribution Window
The time period after an ad click or view during which a conversion is credited to that ad. Meta's default is 7-day click / 1-day view; Google's default varies by conversion action and bidding strategy.
How Do Attribution Windows Work?
Attribution windows define how long after an ad interaction a conversion can be attributed to that ad. If a user clicks a Meta ad on Monday and purchases on Thursday (3 days later), the conversion is attributed to the ad under a 7-day click window but would not be attributed under a 1-day click window. Meta offers four attribution window options: 1-day click, 7-day click (default), 1-day click and 1-day view, and 7-day click and 1-day view. Google Ads supports attribution windows from 1 to 90 days for different conversion actions. The choice of window significantly impacts reported performance — longer windows report more conversions, making campaigns appear more effective.
Why Did Apple’s iOS 14.5 Change Attribution?
Apple’s App Tracking Transparency framework limited Meta’s ability to track user behavior across apps and websites on iOS devices. Before iOS 14.5, Meta used a 28-day click / 1-day view default window with broad cross-site tracking. After iOS 14.5, Meta reduced its maximum attribution window to 7-day click / 1-day view and lost much of its view-through attribution capability for opted-out users. This caused an apparent performance drop for many advertisers — not because campaigns actually performed worse, but because Meta could no longer track the full conversion journey. Server-side solutions like Conversions API partially restore attribution accuracy by sending conversion events directly from the advertiser’s server.
How Do Different Attribution Windows Affect Reported ROAS?
The attribution window directly impacts reported ROAS and CPA. A 7-day click window captures conversions where users research for several days before purchasing, common in high-consideration purchases ($500+ products, B2B software). A 1-day click window only credits immediate conversions, common in impulse purchases and low-consideration items. Switching from 7-day to 1-day click attribution can reduce reported conversions by 20-40% for businesses with longer consideration cycles. Advertisers running both Meta and Google must understand each platform’s attribution methodology to make accurate cross-platform comparisons — otherwise, they risk making budget decisions based on incomparable data.
How Do AI Platforms Normalize Attribution Across Channels?
Cross-platform AI tools address the attribution comparison problem by normalizing conversion data across Meta, Google, and LinkedIn. Each platform uses different default attribution windows and attribution models, making raw platform reports misleading for cross-platform budget allocation. Leo normalizes reporting by applying consistent attribution logic across all platforms, enabling true apples-to-apples performance comparison. This prevents the common mistake of over-investing in the platform with the most generous attribution window while under-investing in platforms that report more conservatively.