Attribution & Tracking
View-Through Attribution Pollution Calculator
The View-Through Attribution Pollution Calculator isolates the false-positive conversions Meta credits to people who only saw your ad, including employees, manual orders, and customers who would have bought anyway. By comparing Meta's reported conversions and revenue against Shopify actuals and your manual orders, it estimates false positives, the false-positive percentage, your true ROAS versus Meta's, and the ad spend wasted optimizing toward the wrong customers. The result reveals how much of your "great ROAS" is noise.
Who it's for: Shopify brands whose Meta-reported ROAS looks too good to be true and who suspect view-through attribution is crediting non-incremental orders.
How the View-Through Attribution Pollution works
You enter Meta reported conversions and revenue, Shopify actual conversions and revenue, Meta ad spend, and your manual or offline orders, all for the last 30 days. The tool calculates the conversion discrepancy (Meta minus Shopify) and its percentage, then subtracts your manual orders to estimate the false positives that view-through attribution likely manufactured.
It computes Meta ROAS from Meta's reported revenue and true ROAS from Shopify's actual revenue, both over the same spend, and expresses the inflation as both an absolute ROAS gap and a percentage. The false-positive share is the estimated false positives over Meta's reported conversions.
Optimization waste estimates the ad spend going toward those false-positive conversions, since Meta's algorithm optimizes toward whatever it counts as a conversion. Based on your false-positive percentage, the tool recommends a specific attribution change, such as switching to 7-day click only above 30 percent, and explains how to make that change in Ads Manager.
The formula
Conversion discrepancy = Meta conversions - Shopify conversions. Estimated false positives = max(0, conversion discrepancy - manual orders). False positive % = (false positives / Meta conversions) x 100. True ROAS = Shopify revenue / ad spend. ROAS inflation % = ((Meta ROAS - true ROAS) / true ROAS) x 100.
Frequently asked questions
What is attribution pollution and where does it come from?+
Attribution pollution is the set of conversions Meta credits to ad views that did not actually influence the purchase. It includes employees who view their own ads, manual or phone orders you created yourself, and organic customers who happened to scroll past an ad before buying. These inflate your conversion count without representing real ad-driven sales.
Why does the calculator ask for manual and offline orders?+
Manual orders such as draft orders and phone orders often get counted as Meta conversions if you or a team member viewed an ad, so they are a known source of false positives. By subtracting them from the raw discrepancy, the tool produces a cleaner estimate of pollution that is not just normal attribution-window variance.
How does optimizing toward false positives actually hurt me?+
Meta's delivery algorithm learns from the conversions it sees and seeks more people like those converters. If a meaningful share of those conversions are false positives, you are teaching the algorithm to chase the wrong audience, which degrades targeting and wastes spend. Reducing pollution lets Meta optimize toward genuinely incremental buyers.
How do I switch to 7-day click only attribution?+
In Meta Ads Manager, open the ad set settings and find the Attribution Setting, then change it from "1-day view, 7-day click" to "7-day click only." This removes view-through credit so reporting reflects clicks that lead to your store. The calculator recommends this change when your false-positive percentage is high enough to materially distort decisions.