Every week, someone asks me why Ads Manager shows 40 purchases when their store shows 31, or the other way round. Both numbers can be "right", because they measure different things. But a large or changing gap usually points to a tracking problem. Here is how to tell the difference.
Why do Meta and your store count differently?
Attribution windows
Meta credits a purchase to an ad if it happens within the attribution window after someone interacted with the ad. The default setting is seven days after a click and one day after a view. Your store counts every order, whatever brought the customer.
View-through conversions
With the default setting, someone who saw your ad (without clicking) and bought within a day can be counted. That buyer may also have clicked a Google ad or come from email, so several channels can claim the same sale.
Reporting date
Ads Manager can report a conversion on the date of the ad impression or click, while your store reports it on the order date. Comparing yesterday's numbers is especially misleading.
Time zone
The ad account time zone and the store time zone may differ, moving orders across days.
When is the gap a tracking problem?
Some causes are not about attribution but about broken data.
| Symptom | Likely cause |
|---|---|
| Meta shows more purchases than your store, every week | Duplicate Purchase events (theme + app, or browser + server without deduplication) |
| Meta shows far fewer purchases | Browser-only Pixel blocked or missed; no Conversions API |
| Purchase value is zero or wrong | Value or currency not sent, or sent before discounts |
| Big sudden change in the gap | A site, theme or checkout update broke an event |
Fixes: deduplicate browser and server events, add the Conversions API and make sure value and currency come from the real order.
How do you compare Meta with real sales properly?
- Use the same date range in both, and allow for the reporting date difference.
- Check the ad account and store time zones.
- In Ads Manager, add columns for different attribution settings (for example seven-day click only) to see how much comes from views.
- In Events Manager, compare total received Purchase events with store orders. This shows tracking health, separate from attribution.
- Calculate a blended number: total revenue ÷ total ad spend across all channels. If it improves while Meta spend grows, Meta is likely contributing.
What about GA4?
GA4 usually shows fewer Meta sales, because it does not count view-through conversions and credits the last non-direct click. That does not mean Meta is wrong; it is a different model. Use GA4 for comparing channels on the same rules, and Ads Manager for optimising inside Meta.
Final thoughts
A stable, explainable gap is normal. A large or changing one is usually tracking. Fix the events first, then compare on the same terms. If you want your numbers checked, see my Meta Ads management service or book a free audit.