A reader wrote in with a puzzle I hear more often than you might think, and it is one worth unpacking properly because the confusion behind it quietly holds a lot of stores back.
Here is the situation. They noticed an order coming through a Shopping campaign that was paused. Then they checked and found Google appeared to be advertising products that were not eligible in any campaign.
Naturally, the worry was: am I being charged for these clicks? They liked the orders, of course, but they had no idea how to switch this off at the campaign level, and no clue how to calculate ROAS when sales seemed to be arriving from a campaign that was switched off.
Sound familiar? Let me walk you through exactly what was happening, because once you see it, a lot of things about how Google Shopping actually works start to click into place.
The "Ineligible" Product That Still Made a Sale
The first thing I wanted to know was what they meant by "ineligible". When Google Ads flags a product as not eligible in any campaign, it is easy to assume the product is invisible on Google entirely. That is not the case.
Here is what was really going on. The reader was looking at the Shopping tab in Google, and they noticed it was just one long section with infinite scrolling. That is the giveaway. Those were all free listings.
Free listings still pull from your product feed. So even though the paid campaign was paused, and even though Google Ads was telling them the product was not eligible for any paid campaign, the item was still appearing as a free listing on the Shopping tab. Google offers these free organic Shopping placements independently of whether you are running paid ads.
The reason it looked so confusing is that their feed carries an ad code query string variable, a little tag on the URL that attributes any resulting order back to the Shopping campaign. So a completely free listing generated a sale, that sale carried the tracking tag, and it showed up looking like it came from the paused paid campaign. No paid click happened. No charge for that click. It was a free listing doing its job.
That distinction between free listings and paid Shopping Ads is the heart of this whole thing, so let me explain why you would ever bother paying when free exists.
Why Pay When You Can List For Free?
This is the big question, and my answer is simple. The number one reason to run paid Shopping Ads, in my opinion, is that they generate roughly 10x more volume than free listings.
That is not a small edge. That is the difference between a trickle and a flood.
And here is the part that most people miss, the part that was tripping up this reader: it is extra volume. Running paid Shopping Ads does not cause you to lose free listing sales. The two work completely independently. Turning paid on does not cannibalise your free traffic.
The 5 Free vs 50 Extra Sales Example
The reader pushed back on this, and it is a fair worry. Their thinking was: if I enable the campaign for this designer brand, surely I am just paying for traffic I would have received for free anyway?
Here is how I explained it, and it is the clearest way I know to think about it.
Imagine paid Shopping Ads are switched off. This month, maybe you generate 5 sales from your free listing. Fine.
Now imagine you switch paid Shopping Ads on. You still receive the same 5 sales from your free listing. That does not change. But now, on top of those 5, you also generate an extra 50 sales from the paid Shopping Ads.
You did not steal those 50 from the free side. Those 50 were never going to happen without paid. They are additional. That is what extra volume means.
The reason this works comes down to where people actually click, so let me show you what the search results page really looks like.
Where People Actually Click on Google
The people browsing that section of the Shopping tab, scrolling through the free listings, will probably click a free listing. Great. You have a listing sitting there ready to capture those shoppers, at no cost.
But here is the thing. Most people do not browse the free listings. Most people never visit the Shopping tab at all.
Most people punch a search term into Google and click the very first thing they see at the top of the main search results page. And for the vast majority of ecommerce search queries, Google fills that premium space at the top with paid Shopping Ads.
Picture the typical layout for a commercial search. From top to bottom you tend to see:
The Search Results Stack
Paid Shopping Ads, right at the very top, the first thing anyone sees.
Paid search text ads, sitting just below the Shopping Ads.
Organic search text results, further down.
Free Shopping listings, further down still.
Notice where the free Shopping listings sit. Way down the page. Notice where the paid Shopping Ads sit. Right at the top, in the premium real estate where most clicks happen.
Most people searching commercial intent ecommerce terms on Google end up clicking a paid Shopping Ads result. If you are running paid Shopping Ads, you have a shot at those people. If you are only on free listings, you are relying on the minority who scroll all the way down or bother to open the Shopping tab.
Of course Google wants people clicking paid ads, because that is how Google makes its money. So Google hands the premium space to the paid results. That is simply the reality of the platform, and you can either play the game or sit it out.
So Should You Turn Paid On?
It comes down to what you want.
If you want as cheap as possible, just run free listings. They cost nothing, they capture the browsers on the Shopping tab, and they carry on quietly making sales in the background whether or not you touch anything else.
If you want to invest some money into playing Google's paid ads game and access that 10x volume sitting in the premium space at the top of the page, then Shopping Ads is the place to be. That is where the real ecommerce volume lives.
For this reader, the answer to their original worry is reassuring. Enabling the campaign for that designer would not mean paying for traffic they would have received for free. The free listing sales carry on regardless. The paid campaign simply opens the door to the much larger pool of shoppers who never touch the free listings in the first place.
Sorting Out Your ROAS
The last piece was the ROAS confusion, and once you understand the free versus paid split, this becomes much clearer.
Free listing clicks cost you nothing. So any revenue attributed to a paused campaign via that ad code query string tag is essentially free revenue, and it is not something you paid to acquire. When you calculate the Return On Ad Spend for your actual paid activity, you want to be comparing the revenue from paid clicks against what you actually spent on those clicks.
The formula itself is straightforward. Take your total revenue from ads over a period, divide it by your total ad spend over the same period. If you generated $5,000 from your Shopping Ads and spent $1,000, your ROAS is 5, meaning five dollars back for every dollar in.
The trap to avoid is lumping free listing sales into your paid ROAS calculation. If those free sales inflate the revenue number while your spend only reflects paid clicks, your ROAS will look artificially rosy and you will make budget decisions on a false picture. Keep the free revenue mentally separate. It is a lovely bonus, but it is not the result of your ad spend.
That is the whole picture. An "ineligible" product quietly making free sales, a tracking tag creating the illusion of a paused campaign generating revenue, and underneath it all the fundamental truth that free listings and paid Shopping Ads work independently, with paid unlocking roughly 10x the volume in the space where people actually click.
Conclusion
Google Shopping runs on two independent tracks, and confusing them causes a lot of unnecessary worry. Free listings pull from your product feed and appear on the Shopping tab whether or not you run paid ads, which is why a product flagged as "ineligible" for paid campaigns can still generate sales. If your feed carries an ad code query string tag, those free sales can look like they came from a paused campaign, when in fact no paid click and no charge ever occurred.
The core lesson is that paid Shopping Ads deliver around 10x more volume than free listings, and crucially, that volume is additive. Switch paid on and you keep your free listing sales while adding many more on top, the classic 5 free versus 50 extra dynamic. This happens because Google places paid Shopping Ads in the premium space at the very top of the results page, above paid text ads, organic results and free listings, which is where most commercial shoppers actually click.
If your priority is minimal cost, free listings alone will tick along. If you want to compete for the bulk of ecommerce traffic, paid Shopping Ads is where the volume is. And when measuring ROAS, keep free listing revenue separate from paid spend so your numbers reflect reality.