Short answer: How do you run Google Shopping ads? Google Shopping ads are fed by the product feed you upload to Merchant Center, and they match searches using product title, GTIN, price and stock data instead of keywords. The setup order is: Merchant Center account, website verification, feed source, shipping and return policies, Google Ads link. Then you launch a Standard Shopping or Performance Max campaign and set your target ROAS above your break-even ROAS. For new accounts, Rebel Co. Group recommends collecting data with Standard Shopping and moving to Performance Max after reaching 30 conversions a month.
Someone who searches Google for "wireless earbuds" sees cards showing product images, prices and store names before any text ads. These cards are Shopping ads, and they make up the most efficient part of Google spend in e-commerce. According to industry reports, the median ROAS of Shopping campaigns is around 5x, well above the overall Google Ads median of roughly 3.3x. That gap comes from the fact that users click after seeing the price: whoever clicks has already accepted it.
However, the performance of a Shopping ad depends far more on the product data in Merchant Center than on campaign settings. A poor title, a missing GTIN, a price that does not match your site and missing shipping information both leave your ads disapproved and push up your cost per click. In this guide, we cover the setup in order, feed quality field by field, disapproval reasons with their fixes, and the Standard Shopping versus Performance Max decision with a comparison table.
How Google Shopping Ads Work
With Shopping ads, it is your product feed, not keywords, that decides which searches you appear for. Google matches the user's search to the title, description, category and attributes in your feed, then ranks your card based on your bid and the quality of your data. That is why there is no such thing as "adding keywords" in Shopping, only fixing titles. The same product can appear in three places: the cards above the search results, the Shopping tab, and surfaces such as Images and YouTube. If you are not yet comfortable with how Google Ads works in general, read our guide to advertising on Google first.
Merchant Center Setup Step by Step
Merchant Center setup consists of five steps, and when you do them in the right order, it takes less than one business day.
- Create the account. Sign in to Merchant Center with a Google business account and enter your business name exactly as the brand name shown on your site. Your address and phone number must match your site's contact page, because a mismatch is the first trigger for a "misrepresentation" review.
- Verify and claim your website. Verify your site through an HTML tag, Google Tag Manager or Search Console, and claim it. If the same domain is already claimed in another Merchant account, it has to be released there first.
- Feed source. There are three options: your e-commerce platform's built-in integration (a few clicks on platforms such as Shopify, ikas, ideasoft and Ticimax), a scheduled XML or CSV fetch, and automatic crawling of your site. If you have more than 500 products, choose a scheduled fetch or an API integration and set up at least one update per day.
- Shipping and return policies. Define the shipping fee and delivery time for Turkey, and if you have a free shipping threshold, enter it as a rule. Add the URL of your return policy page, and make sure that page is actually live on your site. Tax settings are not required for Turkey, since prices are entered in the feed including VAT.
- Google Ads link. Link your Ads account from Merchant Center and approve it on the Ads side. Without the link, your campaign cannot see the feed.
Feed Fields and Quality Rules
Four fields determine feed quality: title, GTIN, image, and price and stock consistency. The other fields matter too, but these four directly affect both approval and cost per click.
| Field | Rule | Common mistake |
|---|---|---|
| title | Brand + product type + distinguishing attribute (color, size, model, volume). The first 70 characters are visible, the limit is 150 | The site title arriving with a promotional word such as "Super Deal" |
| description | 500 to 1,000 characters describing the product, its features and use | HTML tags, all caps, promotional text such as "free shipping" |
| gtin, mpn, brand | Barcode (EAN-13) and brand are required, if there is no barcode set identifier_exists to false | Entering a random code instead of the supplier barcode |
| image_link | White or plain background, product filling at least 75% of the frame, at least 100x100 pixels (250x250 for apparel), no text or logos | A discount badge or watermark on the image |
| price, sale_price | Exactly the same as the price on the site, including VAT, currency TRY | Sale prices reaching the feed late |
| availability | in_stock, out_of_stock or preorder | An out-of-stock product staying in_stock in the feed |
| google_product_category, product_type | Google's taxonomy and your own category path | Assigning every product to a single generic category |
| custom_label_0 to 4 | Your own labels such as margin band, season and sales velocity | Not using them at all and losing the ability to group products |
Field names are the official names of Merchant Center feed attributes. Required fields can vary by country and category, so check the feed diagnostics screen every week.
Title structure
The words that match search intent come first in the title: "Nike Air Zoom Pegasus 41 Men's Running Shoes Black 43" carries brand, model, gender, product type, color and size in a single line. Size and color for apparel, model number and capacity for electronics, and volume for cosmetics should sit in the first half of the title, because on mobile only the first 35 to 40 characters are visible.
GTIN
GTIN lets Google match your product with its own catalog, and products with a correct GTIN get noticeably more impressions than those with a wrong or missing one. For products manufactured in Turkey, barcodes are obtained from GS1 Turkey. For products you make yourself that have no barcode, set identifier_exists to false and do not enter a made-up number, because a mismatch leads to disapproval.
Price and stock consistency
The price in your feed and the price on the product page must be exactly the same. Google crawls the page, and if it finds a difference, it disapproves the product. If prices change hourly during sale periods, take two precautions: add schema.org Product structured data to your product pages and turn on automatic item updates in Merchant Center. That way Google reads the price on the page without waiting for the feed.
Disapproval Reasons and How to Fix Them
Most disapprovals come down to five reasons, and each one has a clear fix.
- Price mismatch: the feed price and the page price differ. Fix: increase update frequency, add structured data, and if you show more than one price on the page, make it clear which one applies.
- Image violation: text, a logo, a badge or low resolution on the image. Fix: use a clean product image and show sale badges through the sale_price field instead of on the image.
- Missing or incorrect GTIN: Fix: get the official barcode from your supplier, and if there is none, set identifier_exists to false.
- Missing policies: return, shipping, contact or payment information cannot be found on the site. This reason leads to suspension at the account level, not the product level. Fix: put all four pieces of information on easy-to-find pages, and make sure your distance sales agreement and return terms are complete.
- Landing page problem: the page returns a 404, loads very slowly or blocks bot access. Fix: check robots.txt and remove broken links from the feed.
If your account is suspended, do not appeal before fixing the problem, because every failed appeal makes the next review take longer.
Standard Shopping or Performance Max
New accounts that have not collected data get better results with Standard Shopping, while mature accounts producing 30 or more conversions a month do better with Performance Max. Both campaign types use the same feed, but the balance between control and automation is completely different.
| Criterion | Standard Shopping | Performance Max |
|---|---|---|
| Search term visibility | Full report, you can add negative keywords | Limited report, negative keywords at account level |
| Placements | Search and the Shopping tab | Search, Shopping, YouTube, Display Network, Gmail, Discover |
| Data requirement | Low, works from day one | At least 30 conversions a month, 2 to 4 weeks of learning |
| Budget control | Bids by product group | By asset group and target ROAS |
| New customer goal | None | New customer acquisition setting available |
| Creative requirement | None, feed only | Image, video and headline assets |
| ROAS benchmark (industry reports) | Shopping median around 5x | Global median 4.8x, roughly 3x for feed-based e-commerce in Turkey |
| Best suited for | New accounts, thin margins, tight control | Mature accounts, large catalogs, scaling |
ROAS figures are approximate medians compiled from industry reports and vary significantly by category and margin structure. Setup details are in our Performance Max guide.
In practice, the healthiest approach is to use both together: run brand searches and your most profitable products in Standard Shopping under tight control, and give Performance Max your wider catalog and the new customer goal. If the same product overlaps in both campaigns, Performance Max takes priority, so split your product groups between campaigns.
Your ROAS Target and Its Link to Margin
Set your target ROAS above your break-even ROAS, with a safety margin that leaves you a profit. A store with a 40% gross margin has a break-even ROAS of 2.5x, meaning every 1 TL of advertising has to bring in at least 2.5 TL of revenue. For this store, a 3.5x target ROAS means 350 TL of revenue and 140 TL of gross profit for every 100 TL of ad spend, which leaves 40 TL of net contribution after the ad cost. You can do the math step by step in our article on break-even ROAS, or with your own numbers in the ROAS calculator.
A single target ROAS cannot be applied to your entire catalog, because products have different margins. The solution is product grouping.
Grouping by profit margin
Give the custom_label_0 field a "high margin", "medium margin" or "low margin" label and set a separate target ROAS for each group. A product with a 60% margin is profitable at 2x ROAS, while a product with a 25% margin loses money below 4x. If you run everything in one campaign with a single target, the algorithm may treat low-margin products as "profitable" and shift budget toward them.
Grouping by sales velocity
Fast-selling products with plenty of stock are scaled with an aggressive target, bids are cut for slow sellers, and products about to run out of stock are removed from the campaign. Give the custom_label_1 field a "fast", "normal" or "slow" label and update it weekly. You can learn how cost per click is formed in our Google Ads costs guide.
In Shopping ads, campaign settings do twenty percent of the work and feed quality does the other eighty percent.
Free Listings
Products you upload to Merchant Center are listed for free in the Google Shopping tab even if you do not advertise. This feature is on by default and covers every product with an approved feed. Free traffic volume is small next to paid traffic, but it costs nothing and it is an indicator of your feed quality: a product that gets no clicks from free listings usually has a title or image that will also perform poorly in ads. You can see free and paid clicks separately in the performance report in Merchant Center.
Common Mistakes and a Weekly Checklist
Most of the mistakes we see in Shopping accounts come not from setup but from a lack of maintenance. Work through this list every week:
- The feed diagnostics screen was opened, and the number of disapproved products and warnings was compared with last week.
- Out-of-stock products are marked out_of_stock in the feed and get no impressions in the campaign.
- Sale prices have reached the feed, and the sale_price and sale_price_effective_date fields are correct.
- Brand searches and generic searches run in separate campaigns, and the brand negative keyword list is active in the generic campaign.
- Target ROAS is set separately by margin group, and the whole catalog is not running on a single target.
- For underperforming products, the title and image were fixed first instead of raising the bid.
- Conversion tracking runs with revenue values, and returned orders are deducted with conversion adjustments.
Google Shopping ads are Google's most efficient surface for e-commerce, but that efficiency only shows up with a clean feed, margin-based target ROAS and regular maintenance. To build the whole process together, from Merchant Center setup to campaign architecture, take a look at our Google Ads agency page, and for your full e-commerce growth, talk to our e-commerce marketing team. Contact us for a free initial consultation.
Frequently asked questions
Is Merchant Center free?
Yes. Opening a Merchant Center account, uploading a feed and showing your products in free listings are completely free. Costs only begin when you launch a Shopping or Performance Max campaign through Google Ads and pay per click. That is why even a store without an ad budget can set up Merchant Center, get organic traffic from the Shopping tab and test its feed quality before advertising.
How often should I update my product feed?
At least once a day, and several times a day if prices and stock change often. Every difference between the price in your feed and the price on the product page gets the product disapproved, and during sale periods this risk multiplies. The safest route is your e-commerce platform's built-in integration or an API connection. In addition, if you add structured data to your product pages and turn on automatic item updates in Merchant Center, Google also reads the price from the page.
Why are my products not approved in Merchant Center?
The five most common reasons are: a mismatch between the feed price and the page price, text, badges or watermarks on the image, a missing or made-up GTIN, missing return, shipping, contact and payment information on the site, and a landing page that returns an error. The first three lead to product-level disapprovals, while missing policies lead to account-level suspension. The feed diagnostics screen clearly states the reason for each product, so do not appeal before fixing it.
Should I start with Standard Shopping or Performance Max?
New accounts, or accounts below 30 conversions a month, should start with Standard Shopping, because you can see search terms, add negative keywords and bid by product group. Once data builds up, move your wider catalog and the new customer goal to Performance Max, and keep brand searches and your most profitable products in Standard Shopping. Do not let the same product overlap in both campaigns, because Performance Max takes priority.
What should the target ROAS be for Shopping ads?
It should be set above your break-even ROAS, with a margin that leaves you a profit. Break-even ROAS is the inverse of your gross margin: 2.5x at a 40% margin, 4x at a 25% margin. Add a safety margin of 30 to 50% on top of that value depending on the category. Instead of applying one target to your entire catalog, group products by margin band with custom labels and give each group its own target, otherwise the algorithm will treat low-margin products as profitable and shift budget toward them.
Can I run Shopping ads for products without a barcode?
Yes. For products you make yourself, handmade goods or custom-made items, set the identifier_exists field in your feed to false and fill in the brand and MPN fields wherever possible. Entering a made-up barcode is the worst option, because a mismatch with Google's catalog gets the product disapproved. For branded products you buy from suppliers, a barcode is required, and you must use a real EAN-13 number registered in the GS1 system.