CSS in Google Ads: Cost Advantage in Product Campaigns

Product ads remain one of the key sales channels in e-commerce. However, they now operate in a completely different environment than a few years ago – Performance Max campaigns dominate, automation is increasing, and auction competition continues to drive up costs.

For medium-sized and large companies, this means one thing: simply being present on Google Shopping is no longer enough. Managing the cost of reaching users and maximizing budget efficiency are becoming increasingly important – especially with large catalogs and significant media investments.

In this context, the use of CSS (Comparison Shopping Services) is becoming increasingly important.

As a result of the European Commission’s 2017 decision, Google was required to open the product advertising space to external price comparison services. The effect of this change is still in place today – in the EU, product ads can be run both through Google Shopping and external CSSs. This has a real impact on costs and competitiveness in the auction.

CSS is a technology partner that enables product ads to be served within the Google ecosystem outside standard Google Shopping.

From the user’s perspective, the difference is minimal – instead of “By: Google,” the name of the comparison service appears below the ad. From a business perspective, the difference concerns click costs and auction efficiency.

CSS operates using its own Merchant Center account and manages the product feed and ad delivery on behalf of the advertiser.

The most important element is the billing model.

With Google Shopping, part of the click cost includes Google’s technological margin. With the CSS model, this margin does not apply – which in practice means:

• lower effective CPC at the same bid,
• greater competitiveness in the auction,
• the ability to achieve better positions with the same budget.

In an environment where bids in product campaigns are increasing year over year, this difference is no longer simply an optimization – it becomes a cost advantage.

Today, most product sales on Google are generated through Performance Max campaigns. CSS also works within this model – it is not a separate campaign type, but rather a layer that affects the costs and efficiency of ad delivery.

This means that:

• campaign management does not change,
• you retain access to Google’s automation and AI,
• you gain a cost advantage behind the scenes across the entire system.

There are many comparison services on the market, but not all of them provide a real advantage. The key question is whether the CSS operates as an intermediary with its own margin or as a tool designed to optimize costs.

At Delante, we use our own CSS – Delante Shopping Platform. This means:

• no additional commission charged by the comparison service,
• full control over the feed and data structure,
• a direct impact of optimization on campaign performance,
• the ability to scale activities without artificially increasing costs.

In practice, with the same budgets, campaigns can generate greater volumes of traffic and sales because a larger share of the investment goes directly into the auction.

The greatest benefits can be seen in cases involving:

• large product catalogs,
• high price competition,
• intensive Performance Max activity,
• pressure on profitability (ROAS / ROI),
• scaling sales while limiting budget increases.

In such scenarios, even a difference of several percent in click cost can translate into tangible business results.

CSS is not an add-on to product campaigns. It is an element that directly affects the cost of reaching users and auction positioning.

In the current Google Ads model, where automation limits manual advantages, it is precisely levers such as having your own CSS that determine campaign efficiency.

That is why, for larger-scale e-commerce businesses, CSS should be treated not as an option, but as a standard part of managing product campaigns.