AI is changing product search: why Google Shopping still matters and the CSS advantage counts
Winning customers is getting harder, and AI assistants are changing how shoppers find products. For online retailers, that means product data and the shop have to convince – and every Shopping budget has to work efficiently.
AI is changing product search – and raising the bar for online retailers
Alongside the economic pressure, customers' buying behaviour is changing. ChatGPT, Google AI Mode and other AI-powered applications open up new ways to discover products and compare them with each other.
Instead of clicking through countless search results, shoppers can state their requirements directly and have suitable products recommended to them. A customer no longer just searches for “running shoes men”, but asks:
Lots of results, the customer compares for themselves.
A short selection, compared and explained.
The AI system can compare different products, explain their features and present a concrete selection. This creates additional requirements for online retailers:
- Products must be findable with complete, up-to-date data and clear descriptions.
- Brand awareness, reviews and credible product experiences can influence purchase decisions.
- Online shops need to convert interested visitors better through convincing product information and simple checkout processes.
At the same time, new paths are emerging by which customers become aware of products, without every contact being directly measurable as a website visit.
Google Shopping remains a core sales channel all the same
The growing importance of AI does not mean that classic Shopping campaigns are suddenly superfluous.
Google Shopping still reaches people with concrete purchase intent. Products are presented directly in the search results with prices, images and retailer information. That is exactly why this channel remains commercially attractive for many online retailers.
However, retailers can less and less afford to simply accept avoidable costs within their campaigns. And this is where an often underestimated lever comes into play.
The Google CSS advantage: bid up to 20% more efficiently
Many online retailers invest considerable budgets in Google Shopping every month without looking more closely at the role of their Comparison Shopping Service (CSS). Yet the choice of CSS partner can have a direct impact on how profitable their Shopping ads are.
What is a Google CSS partner?
CSS stands for Comparison Shopping Service, i.e. a price comparison service. In the European CSS markets, Shopping ads are served through such a service.
That can be Google's own service, Google Shopping. But retailers can also choose an independent CSS partner.
For the online shop, the basic process stays largely the same: products are provided through Merchant Center and campaigns are managed in Google Ads. One of the differences lies in how bids enter the ad auction.
Why an independent CSS partner can save money
Google explains the mechanism itself in its official documentation. In the markets concerned, Google Shopping deducts a margin from the retailer's bid before the bid enters the auction. This margin is included in the cost per click the retailer pays.
Part of the bid goes to Google Shopping as a margin.
Without this margin deduction, the bid enters the auction.
Schematic: same bid, same width. The width of the margin is not to scale.
An independent CSS partner can work without this specific Google Shopping margin deduction. This creates an economic advantage that is often referred to as the up to 20% CSS advantage. Under comparable conditions, this can mean:
- Lower effective click costs at a comparable competitive position.
- More competitiveness in Shopping auctions with the same budget.
- Potentially more clicks and orders without additional ad budget.
The actual effect depends on the auction conditions, the bid strategies and the campaign structure. The CSS advantage is therefore not a guaranteed reduction of every CPC by exactly 20%. How the auction works this out is shown in The 20% CSS advantage: myth, auction mechanics and practice.
Source: Google Merchant Center – Advertising with Comparison Shopping Services
What 20% lower click costs can mean commercially
The financial difference is easy to illustrate. An online shop invests £10,000 a month in Google Shopping. At an average cost per click of £0.50, it gets 20,000 clicks for that.
If the effective cost per click fell by 20% to £0.40 under comparable conditions, the calculation would look like this:
| Metric | Before | After |
|---|---|---|
| Monthly ad budget | £10,000 | £10,000 |
| Average CPC | £0.50 | £0.40 |
| Possible clicks | 20,000 | 25,000 |
| Additional clicks | – | +25% |
Simplified worked example with an assumed 20% CPC reduction (+25% clicks). Not a forecast for your account.
In this simplified example, the same ad budget could therefore pay for 5,000 additional clicks. With an unchanged conversion rate, this would also create a corresponding potential for additional orders. Alternatively, a retailer could try to achieve a comparable click volume with less budget.
Even so, the economic idea is what matters: if a retailer can use their existing Shopping budget more efficiently, they improve their starting position without necessarily having to invest more money in advertising.
Why CSS optimisation should come before a budget increase
When an online shop wants to grow revenue, the first thought is often obvious: increase the ad budget. But before investing additional funds, it is worth asking whether the existing budget is already being used efficiently.
That includes reviewing bid strategies, product feeds, conversion tracking and campaign structures. Another important point is the choice of CSS provider.
Because while many optimisations reach deep into campaign management, a CSS switch can often be implemented without fundamental changes to existing campaigns.
What can stay the same when you switch to an independent CSS
With a regular CSS switch, retailers can in principle keep using their existing infrastructure.
- The existing Google Ads account remains.
- Campaigns and historical performance data are preserved.
- The existing product feed does not fundamentally have to be rebuilt.
- Merchant Center continues to be used for product management.
- Smart Bidding and automated campaigns can continue to be used.
The switch concerns which CSS provider the Merchant Center is assigned to. With more complex MCA structures and individual account permissions, additional steps may be necessary.
Google also describes working with different CSSs and the corresponding switching options in its official documentation. Source: Google Merchant Center – Working with Comparison Shopping Services
That is what makes a CSS switch particularly interesting: retailers do not have to overhaul their entire marketing strategy to use this efficiency lever.
Lower click costs matter – and so do better conversion rates
An independent CSS partner can improve the economics of Shopping advertising. But it does not replace a well-thought-out e-commerce strategy. Whether a click actually turns into a profitable order still depends on the entire shopping experience.
An online shop with unclear product information, high shipping costs or a complicated checkout will waste potential even with cheaper clicks. That is why retailers should work on two sides at the same time:
- 1Lower the cost of winning visitors. Through efficient campaign structures, better product data, suitable bid strategies and an independent CSS partner.
- 2Increase the value of every visitor. Through convincing product pages, helpful buying advice, simple ordering processes and targeted customer retention.
- Efficient campaign structure
- Better product data
- Suitable bid strategy
- Independent CSS partner
- Convincing product pages
- Helpful buying advice
- Simple ordering process
- Targeted customer retention
In an increasingly AI-shaped market in particular, the combination becomes more important. AI may change how users research products. At the same time, Google Shopping remains a relevant channel for concrete purchase intent. And in the end, your own online shop decides how well this interest turns into revenue.
Why a CSS partner can pay off for smaller online shops too
The CSS advantage is not only interesting for retailers with six-figure ad budgets. Possible savings can add up with smaller Shopping budgets too. What matters is the ratio between the achievable advantage and the cost of the CSS provider.
An example: an online shop invests £2,000 a month in Shopping ads. If the CSS switch really did achieve an effective saving of 10% with comparable performance, this would work out at £200 a month or £2,400 a year. The cost of the CSS service would have to be deducted from that.
When choosing a provider, retailers should therefore look for transparent prices, a straightforward technical switch and reliable support.
Conclusion: growing more profitably starts with more efficient Google Shopping campaigns
E-commerce faces a twofold challenge. On the one hand, the economic pressure on customer acquisition is increasing. On the other, AI-powered systems are increasingly changing the way shoppers research products and make purchase decisions.
Online retailers therefore have to do more than simply raise their ad budgets. They need better product data, more convincing shopping experiences and consistent control of their acquisition costs.
An independent Google CSS partner is a particularly obvious measure here. Because before retailers invest additional budget, they should check whether they are already getting the full potential out of their existing Shopping spend.
- Free Google CSS migration
- Full visibility in Google Shopping
- 20% lower click prices
- Visibility in free listings
- 21 EU markets included
- Premium email support
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