Why Meta and Google both claim the same sale.

How can both platforms take credit?

Most people see several ads before they buy. Someone might scroll past your Instagram ad on Monday, search for your brand on Wednesday, click a Google ad and buy. Meta counts that sale because the person saw its ad. Google counts it because the person clicked its ad. Your store records one order.

Neither platform can see the other’s ads, so neither can tell it is sharing the credit. Adding their numbers together double-counts every sale they both touched.

What are attribution windows?

An attribution window is how long after someone interacts with an ad a platform will still claim the sale.

• Meta by default counts a purchase within 7 days of a link click, and within 1 day of someone viewing or engaging with an ad without clicking through. In 2026 Meta separated link clicks from other interactions such as likes, comments and saves, which now sit in their own “engage-through” window.
• Google Ads counts conversions after ad interactions within the window set on each conversion action, and uses data-driven attribution to share credit across Google campaigns. It does not share credit with Meta.

View-through and engagement-based conversions are where most of the overlap comes from. They are not worthless, since ads people see do influence them, but they are the least certain part of the number.

Which number should you believe?

For money decisions, your store orders and your bank. Use the platforms for what they are good at: comparing campaigns, audiences and ads within the same platform. Don’t compare Meta’s reported ROAS with Google’s reported ROAS as if they were measured the same way, because they aren’t.

How do you set budgets without double-counting?

1. Start from total revenue. Track your total store orders and revenue against total ad spend each month. This blended figure can’t be double-counted.
2. Watch what changes. When you raise or cut spend on one channel, look at what happens to total orders, not just that platform’s report.
3. Test where you can. A planned pause in one region, or a holdout test, shows what a channel really adds better than any dashboard.
4. Keep settings consistent. Changing an attribution window changes the reported numbers overnight without changing a single sale. Note any change so month-to-month comparisons stay fair.

Does this mean one channel is wasting money?

Not necessarily. Meta often creates demand that Google later captures when people search. Cutting Meta because Google “gets the sale” can quietly shrink the searches Google depends on. That’s why we plan Google and Meta as one system, from one set of reconciled numbers, rather than letting each platform argue for its own budget.

Platform settings and defaults change often. This guide reflects Google Ads, Meta and Shopify as at 14 November 2026. For the short version, see the related FAQ answer.