An attribution window (also called a lookback window or conversion window) is the period of time after a user interacts with your ad during which a subsequent conversion is credited to that ad. Understanding attribution windows is essential for accurately measuring advertising ROI — a misconfigured window can either overcount conversions (making campaigns appear more effective than they are) or undercount them (causing you to cut profitable campaigns), which is particularly consequential for Indian businesses managing tight digital advertising budgets.
How Do Attribution Windows Work?
When a user clicks your Google Ads advertisement on Monday and makes a purchase on Thursday, the attribution window determines whether that purchase is credited to the ad click. If your window is set to 7 days, the conversion is counted. If it is set to 1 day, it is not.
The key variables are:
- Interaction type: Click-through (user clicked the ad) or view-through (user saw but did not click the ad)
- Window duration: How many days after the interaction conversions are counted
- Attribution model: How credit is distributed when multiple touchpoints exist (last click, first click, linear, data-driven)
What Are the Default Attribution Windows by Platform?
| Platform | Click-Through Default | View-Through Default | Adjustable Range |
|---|---|---|---|
| Google Ads | 30 days | 1 day (where available) | 1, 7, 14, 30, 60, 90 days |
| Meta (Facebook/Instagram) | 7 days | 1 day | 1 or 7 days click; 0 or 1 day view |
| LinkedIn Ads | 30 days | 7 days | 1, 7, 30, 90 days |
| X (Twitter) Ads | 30 days | 1 day | 1, 7, 14, 30 days |
| Google Analytics 4 | 30 days (default) | N/A | 30, 60, 90 days |
How Do You Choose the Right Attribution Window?
The ideal window depends on your product’s buying cycle:
- Short sales cycle (1-3 days): Use shorter windows (1-7 days). Examples: food delivery, impulse purchases, low-cost digital products
- Medium sales cycle (1-2 weeks): Use 7-14 day windows. Examples: clothing, electronics, event tickets
- Long sales cycle (2-8 weeks): Use 30-90 day windows. Examples: B2B services, enterprise software, high-value purchases, education courses
- SaaS and subscriptions: Use longer windows (30-60 days) as users often research extensively before committing to recurring payments
For Indian B2B services like digital marketing, web development, or cyber security consulting, the consideration phase can be weeks or months, making 30 to 90 day click-through windows appropriate.
Why Is View-Through Attribution Controversial?
View-through conversions count when a user sees your ad (an impression) but does not click, then later converts through another channel. The controversy:
- Overattribution risk: Display and video ads reach millions of impressions. Crediting conversions that were going to happen anyway inflates campaign performance
- Valid signal: Brand awareness campaigns genuinely influence future purchase decisions even without clicks. Ignoring view-through entirely undervalues awareness
- Platform incentive: Ad platforms benefit from wider attribution (more conversions attributed means campaigns look more successful), creating a conflict of interest
Recommendation: use a 1-day view-through window at most, and always compare against a control group or holdout test to validate that view-through conversions represent genuine lift.
How Do Attribution Windows Affect Budget Decisions?
Mismatched windows across platforms create comparison problems:
- Google Ads with 30-day click attribution will show more conversions than Meta with 7-day click attribution for the same campaign effectiveness
- Shortening Meta’s window from 28 days (the old default) to 7 days reduced reported conversions significantly — campaigns did not get worse, just the measurement changed
- Always compare platforms using the same attribution settings, or use a third-party analytics tool (like GA4) as a single source of truth
Should I use data-driven attribution or last-click?
Google Ads now defaults to data-driven attribution (DDA), which uses machine learning to distribute credit across touchpoints. For accounts with sufficient conversion data, DDA typically provides more accurate credit distribution than last-click. However, for small Indian businesses with fewer than 300 conversions per month, the model may lack enough data to be reliable. In that case, last-click provides simpler, more predictable measurement.
How do iOS privacy changes affect attribution windows?
Apple’s App Tracking Transparency (ATT) significantly impacted Meta’s attribution capabilities. Users who opt out of tracking are not included in view-through and some click-through attribution. Meta now relies more on modeled conversions (statistical estimates) to fill gaps. For Indian advertisers, the impact is smaller than in Western markets (higher Android usage) but still relevant for iOS-heavy audiences in metros.
Can different products have different attribution windows?
Yes, and they should. In Google Ads, attribution windows are set at the conversion action level, so you can assign a 7-day window for low-cost product purchases and a 30-day window for high-value service enquiries within the same account. This reflects the different buying cycles and provides more accurate measurement for each product type.
How do I audit my current attribution settings?
In Google Ads, go to Goals, then Conversions, then Settings to see each conversion action’s attribution model and window. In Meta Ads Manager, check the attribution setting in your ad set’s optimisation section and compare reported conversions using different windows in the reporting columns. In GA4, check attribution settings under Admin, then Attribution Settings to see the default model and lookback window.
