More than the report says, and the way to find out is not in the campaign view. Segment new versus returning at the conversion level, then check which campaigns are intercepting demand rather than creating it.

On this page

• What are the two ways non-brand spend reaches existing customers?
• How do I measure how much spend reaches repeat buyers?
• Should I switch off campaigns that harvest existing customers?
• Is paid search picking up repeat buyers actually an email problem?

What are the two ways non-brand spend reaches existing customers?

The obvious one: campaigns explicitly targeting past buyers — remarketing lists, customer match audiences — counted inside an acquisition budget. Easy to spot, easy to separate.

The one that costs more: campaigns nominally targeting new demand that are in practice harvesting people already on their way to buying. Bottom-of-funnel Shopping is the classic. It looks like non-brand. It is credited like acquisition. It is neither.

The signature on one account: 8,232 first-time orders at $1.97 each. No acquisition channel produces customers at $1.97. That is the number of a channel catching people who had already decided.

How do I measure how much spend reaches repeat buyers?

1. Turn on new-versus-returning reporting and segment conversions by it. If your store passes the signal, this is a column, not a project.
2. Compute cost per new customer per campaign, not cost per conversion. The gap between the two is the returning-customer share.
3. Rank campaigns by that gap. Anything with an implausibly low cost per new customer is a harvester regardless of its name.
4. Recompute your acquisition cost with harvesters stripped. On the account above, that moved the reported figure from about $15 to about $30.

Should I switch off campaigns that harvest existing customers?

Not necessarily turn them off. A harvester at $1.97 is cheap insurance against losing a sale at the last step, and switching it off is how people discover it was doing something after all.

The point is accounting, not elimination. Put harvest campaigns in their own bucket with their own target, and judge genuine acquisition on its own number. Then a budget decision about growth is made against the number that actually governs growth.

Is paid search picking up repeat buyers actually an email problem?

If a large share of non-brand spend reaches people who already bought, the question is not only "how do I stop paying for them" but "why is my retention channel not reaching them first." Paid search picking up repeat buyers is often an email problem wearing a Google Ads costume.

Related questions

How do I find out how much of my Performance Max spend is going to my own brand searches?

Performance Max does not report brand spend as a line item, so you build it from the search terms it does expose plus the network split — and accept that the figure is a floor, not a total. Read the full answer.

Why can't I see all my search terms in Google Ads, and how much of my spend is hidden?

Google withholds terms that were not searched by "a significant number of users," which on most accounts leaves a material share of spend unattributed to any visible query. The fix is not to recover the terms — it is to stop needing them. Read the full answer.

Are Demand Gen conversions real, or is Google taking credit for people who saw the ad and never clicked?

Both, and the honest answer is that the truth sits between the two numbers. Demand Gen is structurally a view-through channel, so a clicks-only model gives it zero credit and a view-inclusive model flatters it — and the gap between them is very large. Read the full answer.

Written by Usama Khan, who runs Google Ads for e-commerce brands and home-services companies at AdventurAds. Figures are from accounts under active management and are anonymised. Last reviewed 2026-08-26.