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CSS Partner Case Studies: What 20-40% Lower CPC Looks Like in 90 Days
2026-05-30
The promise of a Comparison Shopping Service is simple: around 20% lower cost-per-click on Google Shopping. But what does that actually do to a real shop's numbers over a quarter? This article walks through worked example scenarios at different spend levels, so you can see how the saving plays out and estimate what it would mean for your own account.
Important: all numbers in this article are example figures for illustration. They are constructed scenarios, not claims about specific named clients or guaranteed results. Your actual saving depends on your category, bids, competition and how you choose to spend the headroom. The mechanism, around 20% lower CPC from an authorised CSS, is real and EU-mandated; the specific figures below are illustrative.
How the saving shows up
A CSS lowers your cost-per-click. That single change can be taken in two directions, and shops choose differently:
- Bank the saving. Keep bids and budget the same, and your monthly Shopping spend falls by roughly the CPC reduction while you keep the same traffic.
- Reinvest the saving. Keep your budget the same and raise bids or volume, so you get more clicks and more conversions for the same spend.
Most of the scenarios below assume a mix, which is what shops tend to do in practice once they see the headroom.
Scenario A: small shop, 800 € per month Shopping spend
Example figures.
A small homeware shop spends 800 € per month on Google Shopping at an average CPC of 0.40 €, so roughly 2,000 clicks per month.
After moving to an authorised CSS, the average CPC drops by around 20% to 0.32 €.
- If the shop banks the saving: the same 2,000 clicks now cost about 640 €, a saving of around 160 € per month, or roughly 480 € over the first 90 days.
- If the shop reinvests: holding the 800 € budget steady at 0.32 € per click yields about 2,500 clicks, roughly 25% more traffic for the same spend.
Against a CSS subscription of 20 € per month (about 20 €), the net gain is positive from the first month at this spend level.
Scenario B: mid-size shop, 5.000 € per month Shopping spend
Example figures.
A mid-size fashion retailer spends 5.000 € per month on Shopping at an average CPC of 0.50 €, so about 10,000 clicks.
After the CSS, CPC falls by around 20% to 0.40 €.
- Banking the saving: the same 10,000 clicks now cost 4.000 €, a saving of about 1.000 € per month, or roughly 3.000 € over 90 days.
- Reinvesting: the 5.000 € budget at 0.40 € per click buys about 12,500 clicks, roughly 2,500 extra visits per month at no extra cost.
At this scale the saving dwarfs the subscription many times over, every month.
Scenario C: larger multi-country shop, 20.000 € per month across five markets
Example figures.
A larger shop sells across five CSS countries and spends 20.000 € per month on Shopping at an average CPC of 0.45 €, about 44,000 clicks.
After the CSS, CPC falls by around 20% to 0.36 €.
- Banking the saving: the same traffic now costs about 16.000 €, a saving of roughly 4.000 € per month, or around 12.000 € over 90 days.
- Reinvesting: the 20.000 € budget at 0.36 € per click buys about 55,000 clicks, roughly 11,000 extra visits per month.
Because a flat-fee CSS includes all countries in one subscription, this shop pays 20 € per month total, not per country, so the per-country overhead that a percentage-of-spend provider would add does not apply.
Where the "20-40%" range comes from
The headline number for the saving is around 20%, the structural average. Some shops in some categories see more, into the 25 to 40% range on parts of their account, while others see closer to 15%. The variation comes from category competitiveness, current bid levels and how concentrated spend is on high-cost clicks.
When a scenario reaches the higher end, it is usually because the shop also reinvested the CPC headroom into more volume, so the combined effect on traffic and efficiency over a quarter looks larger than the raw CPC change alone. These dynamics are why we describe a range rather than a single guaranteed figure, and why every number here is explicitly an example.
What does not change in any scenario
Across all three scenarios, the things that stay identical are worth repeating:
- The ads look the same to shoppers. Same products, same prices, same placements.
- The Google Ads account, campaigns, bids and feed stay under the shop's control.
- There is no downtime, no relearning phase and no change to ranking or Quality Score.
- The only change is which CSS is linked to Merchant Center, and the resulting CPC.
How to estimate your own numbers
You can sketch your own scenario in three steps:
1. Take your current monthly Shopping spend and average CPC from your Google Ads account. 2. Apply a 20% CPC reduction. That gives you either the spend saving (same clicks, lower cost) or the extra clicks (same budget, more traffic). 3. Subtract the CSS subscription of 20 € per month. For any shop spending more than a few hundred euros per month on Shopping, the net result is positive in month one.
For a more precise estimate tied to your actual account, the honest approach is to look at your real CPC and spend rather than rely on any example figures, including these.
The bottom line
A roughly 20% lower cost-per-click is a meaningful number once you put it against real spend: hundreds of euros saved per month for a small shop, thousands for a larger one, every month, against a flat 20 € subscription. The scenarios here are example figures to show the shape of the saving, not guarantees. Run your own spend and CPC through the same simple arithmetic and you will see what it means for you.
See how a CSS lowers CPC, check the pricing, or get started.
Frequently asked questions
Are these real client results?
No. Every figure in this article is an example scenario constructed for illustration. They show how a roughly 20% CPC reduction plays out arithmetically at different spend levels. The CPC mechanism is real and EU-mandated; the specific numbers are not claims about named clients.
Will I definitely see 20% lower CPC?
The 20% is a structural average. Most shops see 15 to 25%, with some categories and accounts seeing more. Your figure depends on your category, bids and competition. We do not guarantee a specific number, because no honest CSS can.
Should I bank the saving or reinvest it?
That is your choice and we do not touch your campaign settings. Banking it lowers your spend for the same traffic; reinvesting it grows your traffic for the same spend. Many shops do a mix.
Does the saving apply across all my countries?
Yes, in every CSS market you advertise in, and with a flat-fee CSS all countries are included in one subscription rather than charged per country.
See it on your own account
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