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Why Meta, Google Ads and Shopify report different sales, and which number to trust

By Kristoffer Nielsen, Wield · Published

Short answer

Meta, Google Ads and Shopify each count sales by their own rules. Meta and Google credit a sale to their ad if it was clicked or seen within a time window, so the same order is often claimed by both. Shopify counts each order once, using the last marketing channel. Use Shopify for total sales, each ad platform to compare its own campaigns, and total sales divided by total ad spend to judge whether ads are working.

Why the numbers never match

Each platform answers a different question: “did our ad play a part in this sale?” for Meta and Google, and “which channel brought this order in last?” for Shopify.

What counts as “its” sale Time window Date the sale is reported on
Meta (Facebook, Instagram) A purchase after someone clicked or saw your ad Commonly 7 days after a click and 1 day after a view; check the Attribution setting column in Ads Manager Meta’s own reporting date
Google Ads A conversion after someone clicked (or saw) your ad 30 days after a click by default, 1 day after a view The date of the ad click, in the standard columns
Shopify Each order once, credited to the last marketing channel, ignoring direct visits The visit that led to the order The date of the order

Three things follow from this:

  1. The same order is claimed twice. A shopper clicks an Instagram ad on Monday, searches your brand on Google on Wednesday, clicks your search ad and buys. Meta counts the sale (click within 7 days). Google counts it (click within 30 days). Shopify gives it to Google only.
  2. Ad platforms see views as well as clicks. Meta can count a sale from someone who only saw your ad and then bought a day later through an email. Shopify will never give that order to Meta.
  3. The days don’t line up. Google Ads puts conversions on the click date, so last week’s figures can still change this week, and yesterday’s Google number will look low next to Shopify.

So if you add up “purchases” from Meta and Google, you’ll usually get more orders than you actually had. That’s normal, not a bug.

An example week

A store has 100 orders in a week:

Source Orders it reports
Meta Ads Manager 45
Google Ads 40
Meta + Google together 85
Shopify, credited to Meta 30
Shopify, credited to Google Ads 25
Shopify, everything else (email, organic search, direct) 45

Nobody is lying. Meta and Google each saw their ad somewhere in the path to more orders than Shopify credits them with. The numbers are illustrative.

Which number to use for which decision

Question Use Why
How much did we sell? Shopify It’s the money that actually came in
Which Meta campaign or ad works best? Meta Ads Manager Same rules across all your Meta campaigns, so the comparison is fair
Which Google campaign works best? Google Ads Same reason
Should money move from Meta to Google, or back? Shopify’s marketing report, with one attribution model for both One set of rules for both platforms
Are our ads paying off overall? Blended ROAS (MER) Can’t be double-counted

Blended ROAS, often called MER (marketing efficiency ratio), is your total store sales divided by your total ad spend for the same days. If you sold $38,000 and spent $2,100 on all ads, your MER is about 18. It doesn’t tell you which ad did the work, but it can’t be inflated by two platforms claiming the same order. Watch it week by week: if it holds steady while you shift budget between platforms, the shift didn’t hurt.

The gaps you can fix

Some differences are by design. These ones are mistakes:

  • No campaign tags on Meta ads. Shopify can only credit Meta if the click arrives with tracking tags. Add UTM parameters in the URL parameters field of every Meta ad (for example utm_source=facebook&utm_medium=paid). Google Ads clicks are recognised through auto-tagging, so keep it switched on.
  • The purchase is counted twice by one platform. Two Meta pixels, or a pixel plus a server connection that isn’t set up to remove duplicates, can count one order twice. In Events Manager, compare a day’s purchases with Shopify’s orders for that day. On Google, check the purchase conversion action isn’t installed twice (for example by both a theme snippet and the Google & YouTube app).
  • Comparing different days. Google Ads uses the click date. Add the “Conversions (by conv. time)” and “Conv. value (by conv. time)” columns when you compare with Shopify.
  • Comparing different money. Shopify’s total sales and the conversion value an ad platform receives may treat tax, shipping, discounts and refunds differently. Check what your purchase event sends before comparing values.
  • Different time zones. Your ad accounts and store may run on different time zones, which shifts orders between days. Check each account’s time zone setting.

A five-minute weekly check

  1. Note last week’s Shopify total sales and total ad spend across all platforms. Work out the blended ROAS.
  2. Compare it with the week before and the same week last year.
  3. In Shopify’s marketing report, check which channels got credit, using one attribution model.
  4. In each ad platform, compare campaigns only with each other.
  5. If one platform’s purchases jumped but Shopify’s sales didn’t, check that platform’s tracking first.

Questions people also ask

Why does Meta show more purchases than Shopify?

Meta counts a purchase if someone clicked one of your ads within its click window or saw one within its view window, even if they later came back through Google, email or a direct visit. Shopify gives that order to the last channel instead. Check the Attribution setting column in Ads Manager to see which windows your ad sets use.

Why don't Google Ads conversions match Shopify for yesterday?

Google Ads reports conversions on the date of the ad click, not the date of the purchase, so a click last week that buys today counts toward last week. Add the "Conversions (by conv. time)" column to compare with Shopify's daily numbers.

Which attribution model does Shopify use?

Shopify's marketing reports use last non-direct click by default: the order goes to the last channel the customer came through, ignoring direct visits. You can switch to other models such as first click or linear in the report's Attribution menu.

What is a good blended ROAS (MER)?

There's no universal number: it depends on your margins. Work out the ratio at which ads break even after product costs, shipping and fees, then watch whether your weekly figure stays above it.

Should I just trust one platform?

Trust each for the question it answers best. Shopify for what you sold, each ad platform for which of its own campaigns works better, and blended ROAS for whether your total ad spend pays off.

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