How do I pause a channel to test it?

Usually, pause it in some regions and keep it running in the rest, rather than switching it off everywhere. Turn off every campaign that buys that channel in the paused regions, then compare total store sales between the two groups. Run longer than your buyers take to decide, and judge the gap against a line you wrote down first.

Switching a channel off everywhere and watching the totals feels like an experiment. It is a before-and-after comparison, and everything else that changed that month gets a vote. A pause becomes a test when three things hold:

• Something keeps running for comparison. Regions that keep the channel show what the paused regions would have sold.
• Off really means off. Every campaign that can buy the channel stops there, not just the one named after it.
• You read the result where the money lands. The paused channel's own report drops to zero by design. That tells you the switch worked, and nothing else.

What one store's data shows

One store's anonymised GA4 export, 1 January 2024 to 21 August 2026. It holds shares of revenue only: no ad spend, no order counts.

Read the table the way a pause would. In that store's Channels sheet, Direct holds 57.7% of revenue whether you credit the last click, the first click or every touch. Nobody can switch Direct off, and nobody sends you an invoice for it.

That changes what you measure. When a paid channel goes quiet, some of its buyers still arrive by typing the address. Their sales move into Direct, so the paused channel's row falls further than your sales do. Judge the pause on total sales by region, never on the row you switched off.

The Journeys sheet adds a timetable. Journeys with 1 touch carry 79.5% of that store's revenue, and those buyers took 0.5 days to buy. If a paused channel fed journeys like those, the dip shows in the first week.

The slower lane runs on another clock. In that store's Journeys sheet, journeys with two or more touches hold 20.6% of revenue. On the same Journeys sheet, those with 4 to 9 touches took 16.9 days to buy. A pause cuts some of those journeys halfway. Their missing sales land two or three weeks later, often after the channel is back on.

So the weeks after the restart belong to the test. Google's Meridian documentation describes media effects that taper off slowly over time. They don't stop on the day you flip the switch, in either direction. Keep counting until the slow journeys have had time to finish.

The export can't say which channel fed Direct, or what any pause would cost or return. It holds no spend and no order counts. It shows where to look, and for how long.

Where do the missing sales go?

A pause rarely deletes sales cleanly. Some vanish, and some walk in through another door. Know the doors before you start, or the result will look gentler than the cut.

• Into another campaign. Google's Performance Max can serve on Search, YouTube, Display, Discover, Gmail and Maps from one campaign. Google gives a Search campaign priority over it when a query hits one of its exact match keywords. Pause Search and Performance Max can bid on those queries instead.
• Into your free results. When search ads stop, some searchers click your organic listing. Google researchers who pooled 390 Search Ads Pause studies found limited room for organic clicks to replace ad clicks.
• Into Direct. Some people who would have clicked an ad type your address instead. No channel gets the credit, which is why the totals matter.
• Out of the door. If shoppers can buy the same thing elsewhere, some will. That sale is gone, and it is the part of the loss the test exists to catch.

Decide in advance which doors stay open. Leave Performance Max running if you would keep it after a cut. Switch it off in the same regions if you want the paused channel's full effect.

GA4 helps you watch the doors. It files Performance Max visits under Cross-network, and visits from Google's free product listings under Organic Shopping. Check both rows in the paused regions.

What can a pause not tell you?

• What two channels do together. If Meta and Google reach the same buyers, each covers for the other. Pause one and the other catches many of its buyers, so the loss looks small. Pause both and the loss can exceed the two small results added up. If you plan to cut both, test them together.
• What a long silence would do. A few dark weeks show the fast part of a channel's work. People's memory of your name builds and fades over months. A short pause can undersell a channel whose work is slow.
• Whether the channel or the campaign failed. A pause grades the campaigns you ran, with today's creative, targeting and budget. A weak campaign can fail where a better one would pass. Read a flat result as a verdict on what ran.

What to do this week

1. Map every campaign that can buy the channel. Start with Performance Max in Google Ads. Go to Campaigns within the Campaigns menu, open the Insights and reports drop-down and select Channel performance. Pass: none serves the channel you plan to pause, or you have decided it stays on. Fail: one serves it and nobody counted it, so add it to the plan.
2. Save the scoreboard before you touch anything. In Shopify, go to Analytics > Reports, filter the Category by Customers and open Customers by location. It counts new customers by region, placed at their most recent shipping location. Pass: you can list new customers for the regions you would pause and the ones you would keep. Fail: one region holds most of them, so plan to split by city or postal code.
3. Read last month's change log. In Google Ads, go to Change history within the Campaigns menu and scan the past four weeks. Pass: a handful of planned edits, so a quiet test window is realistic. Fail: budgets and bids moved every few days, so agree a freeze for the test weeks first.

Check the homework. Your GA4 Attribution paths export already holds the evidence. Causality Engine reads that one file and shows what each channel caused next to what last-click gave it, in 1 to 2 minutes, for €99 once (excluding VAT), refundable within 30 days. Check the homework

Sources, 1 October 2026: About Performance Max campaigns (Google Ads Help); Impact Of Ranking Of Organic Search Results On The Incrementality Of Search Ads (Google Research); Media saturation and lagging (Google for Developers (Meridian)); Default channel group (Google Analytics Help); About the channel performance report for Performance Max (Google Ads Help); Customers reports (Shopify Help Center); About change history (Google Ads Help); Implement campaigns for geo experiments (Google Ads Help).

Related answers

• All Incrementality questions
• How to pause an ad channel for a test, step by step
• How should an electronics store pause a channel to test it?
• Incrementality testing, explained
• Geotargeting, in the glossary