Getting Started with CSS - Your First Steps

Switching to an independent CSS partner is one of the fastest optimizations you can make to your Google Shopping campaigns. The process takes minutes, requires no changes to your campaigns or product feed, and the CPC savings begin immediately. This guide walks you through every step.

Prerequisites

Before you switch CSS, make sure you have the following in place. Most merchants running Shopping ads already meet all of these requirements.

• A Google Ads account with active Shopping campaigns or Performance Max campaigns that include Shopping placements.
• A Google Merchant Center account linked to your Google Ads account, with your website verified and claimed.
• Approved products in your Merchant Center feed. Your products should be in "Active" status, meaning they have passed Google's feed review and are eligible to appear in Shopping ads.
• Active Shopping or Performance Max campaigns currently running in Google Ads. CSS reduces the cost of Shopping clicks, so you need active campaigns to benefit from the switch.

If you are not yet running Shopping ads, you will need to set those up first. See our guides on Shopping Campaigns and Performance Max for details on getting started with Shopping advertising.

The Four-Step Process

Here is the step-by-step process for switching to Cobiro CSS. The entire process typically takes less than five minutes.

Step 1: Create Your Cobiro Account

Visit cobiro.com and create a free account. You will need an email address and a password. No credit card is required to start the free trial. The account setup takes less than a minute.

Step 2: Connect Your Merchant Center

In the Cobiro dashboard, enter your Google Merchant Center ID. This is the numeric identifier for your Merchant Center account, which you can find in Merchant Center under Settings > Account Information. It is typically a 9-10 digit number. Cobiro uses this ID to send the CSS association request to your Merchant Center.

Step 3: Activate CSS

After Cobiro sends the association request, you need to accept it in your Google Merchant Center. Log into Merchant Center, navigate to Settings > CSS, and you will see a pending invitation from Cobiro. Click to accept the invitation. This step confirms that you authorize Cobiro to act as your CSS partner.

If your agency manages your Merchant Center, your agency can accept the invitation on your behalf. The key requirement is that someone with admin access to the Merchant Center account accepts the CSS association.

Step 4: Done

That is the complete process. Once you accept the CSS association, your Shopping ads automatically benefit from the CSS advantage. There is nothing else to configure, no campaigns to update, and no settings to change in Google Ads. The reduced CPC margin applies to all Shopping auction entries from your Merchant Center going forward.

What Changes After Switching

Only two things change when you switch to an independent CSS partner. Everything else stays exactly the same.

The "By" Label

Your Shopping ads will display a small "By Cobiro" label (or whatever your CSS partner's name is) instead of "By Google." This label appears in small text beneath the ad and is part of Google's transparency requirement from the 2017 ruling. Multiple studies have shown that this label has no measurable impact on click-through rates or conversion rates. Shoppers focus on the product image, price, and merchant name, not the CSS attribution text.

CPC Costs

Your effective cost per click on Shopping ads drops by approximately 20%. This happens because Google Shopping Europe (GSE) applies a margin to bids submitted through its own service, and independent CSS partners do not carry this margin. The saving applies to standard Shopping campaigns, the Shopping component of Performance Max campaigns, and Local Inventory Ads. For a full explanation of the mechanics, see How the Discount Works.

What Does Not Change

Understanding what stays the same is just as important as understanding what changes. Here is the complete list of things that are unaffected by a CSS switch.

• Your Google Ads campaigns. Campaign structure, ad groups, product groups, targeting settings, scheduling, and all other campaign configurations remain untouched.
• Your bids and budgets. All bidding strategies (manual CPC, Enhanced CPC, Target ROAS, Maximize Conversions) continue to work as before. Your daily and monthly budgets are unchanged.
• Your product data. Your Merchant Center feed, product titles, descriptions, images, prices, availability, and all other product attributes are completely unaffected.
• Your quality scores. Product quality ratings, landing page experience scores, and relevance scores are determined by Google based on your products and website, not by your CSS partner.
• Your conversion tracking. All conversion tracking, attribution models, and reporting in Google Ads remain the same.
• Your ad placements. Shopping ads appear in the same locations regardless of CSS: the Shopping carousel in Search results, the Shopping tab, Google partner sites, and Shopping placements within Performance Max.
• Your historical data. All historical campaign data, performance metrics, and conversion history are preserved. There is no data reset or loss.

Timeline

The CSS activation process follows this timeline:

• Account creation and MC connection: 2-5 minutes (self-service through Cobiro).
• CSS association acceptance: Immediate once you accept in Merchant Center.
• CPC advantage activation: Takes effect as soon as the association is active. New Shopping auction entries from your Merchant Center immediately benefit from the reduced margin.
• "By" label update: The label on live Shopping ads updates within 24-48 hours. This is a cosmetic change and does not affect when the CPC savings begin.
• Smart Bidding recalibration: If you use automated bidding strategies (Target ROAS, Maximize Conversions, etc.), the algorithms will detect the improved auction efficiency and adjust within a few days. Do not manually lower your bids during this period.

From start to finish, the self-service process takes minutes. Full activation, including the "By" label update and Smart Bidding recalibration, is typically complete within 24-48 hours.

Verification

After switching, you can verify that your CSS is active through two methods.

Check Merchant Center Settings

Log into Google Merchant Center and navigate to Settings > CSS. You should see your new CSS partner (for example, Cobiro) listed as your active CSS. The status should show as "Active" or "Approved." If the status shows "Pending," the association has not yet been accepted.

Look for the "By" Label on Shopping Ads

Search for one of your products on Google and look at the Shopping ads in the results. Below your ad, you should see "By Cobiro" (or your CSS partner's name) instead of "By Google." Note that this label may take 24-48 hours to update after activation, so do not be concerned if you still see "By Google" immediately after switching.

Common Questions

Can I switch back to Google Shopping Europe?

Yes. The CSS switch is fully reversible. You can return to GSE at any time by removing the CSS association in your Merchant Center settings. There is no penalty, no lock-in, and no data loss. However, switching back to GSE means your Shopping CPCs will return to the higher rate that includes Google's margin.

Can I use multiple CSS partners simultaneously?

A Merchant Center account can only be associated with one primary CSS at a time. However, if you have multiple Merchant Center accounts (for example, separate accounts for different countries or business units), each account can use a different CSS partner.

Do I need to tell Google Ads about the switch?

No. The CSS switch is handled entirely in Merchant Center. Google Ads is not involved in the process, and no changes are needed in your Google Ads account. Your campaigns will automatically benefit from the CSS advantage without any action in Google Ads.

Will my campaigns stop running during the switch?

No. Your Shopping campaigns continue running without interruption during the CSS switch. There is no downtime, no pausing, and no re-approval process. The transition is seamless.

What if I use an agency to manage my Google Ads?

Your agency can handle the CSS switch for you, or you can do it yourself. The CSS association is in Merchant Center, which is separate from Google Ads account access. If your agency has admin access to your Merchant Center, they can accept the CSS association on your behalf. If they do not have Merchant Center access, you will need to accept the invitation yourself. Either way, no changes are needed in Google Ads.

Does CSS work with Performance Max campaigns?

Yes. The CSS advantage applies to the Shopping placements within Performance Max campaigns. Since PMax includes multiple ad formats (Shopping, Search, Display, YouTube, Discover, Gmail), the approximately 20% CPC reduction applies specifically to the Shopping component. For a detailed guide, see Performance Max and CSS.

For a comprehensive understanding of CSS terminology, see the Glossary. To compare CSS providers before making your choice, see Choosing a CSS Partner.