E-commerce businesses running Google Ads typically have access to two fundamentally different ad formats: Google Shopping (now part of Performance Max or standard Shopping campaigns) and standard text search ads. Both appear in search results; both drive traffic to product and category pages; but they operate through different mechanisms, require different optimisation approaches, and suit different products and buying contexts. Understanding when each delivers better return helps you allocate budget to the format that performs best for your specific products and customer journey.
How Do Google Shopping Ads Work?
Google Shopping ads are product listing ads that appear at the top of search results with a product image, price, retailer name, and star rating. They are triggered by Google matching search queries to products in your Merchant Centre feed, rather than by keywords you have explicitly bid on.
The feed-based nature of Shopping is both its strength and its complexity. You control visibility by optimising the product data you submit: product titles, descriptions, categories, and attributes. Google then uses this data to match your products to relevant queries algorithmically. You bid at the product, product group, or category level, and Google determines which specific queries your ads show for.
Shopping ads appear for product-intent queries: "red running shoes size 8," "king size duvet 13.5 tog," "Canon DSLR camera under £500." These are queries from buyers who have identified a product type and are looking for options and prices.
How Do Standard Search Ads Work for E-Commerce?
Standard search ads are text-based ads triggered by keywords you choose. They appear above and below organic search results with a headline, display URL, and description. For e-commerce, search ads are typically used for:
- Category-level queries ("women's running shoes UK", "office chairs")
- Brand comparison queries ("Nike vs Adidas running shoes")
- Feature-specific queries ("running shoes for flat feet UK")
- High-intent queries that do not return Shopping results prominently ("bespoke engagement ring London")
Unlike Shopping, you control precisely which queries trigger your ads through keyword selection and match type. You also control the ad copy: the headline, description, and display URL are all written by you. This control means search ads can be highly tailored to specific customer intents and can include messaging that Shopping ads cannot (offers, guarantees, differentiators).
Which Format Generates Better ROI for E-Commerce?
The answer depends on your product type, your price point, and the stage of the buying journey you are targeting.
When Shopping Ads Outperform Search Ads
Commodity and comparison products: Products where price and availability are the primary purchase decision factors. Electronics, homeware, fashion basics, sporting equipment, and other categories where shoppers compare options based on price, ratings, and availability are naturally suited to Shopping. The visual format with price visible in the ad allows buyers to pre-qualify before clicking, which means Shopping clicks are more purchase-intent qualified.
Products with strong visual appeal: Photography equipment, clothing, furniture, jewellery, and other categories where the product image is a primary purchase signal. Shopping ads that show an attractive product image generate higher CTR for visually driven categories than text ads.
Lower average order values: For products in the £20 to £200 range, Shopping campaigns typically deliver lower CPCs than search campaigns for equivalent traffic quality, making the economics more efficient.
Broad product discovery: When buyers are browsing rather than searching for a specific product, Shopping format supports the discovery process more naturally. A buyer searching "kitchen accessories" can browse multiple Shopping results visually in a way that text ads do not facilitate.
When Search Ads Outperform Shopping Ads
High-value, considered purchases: For products where the buying decision is complex, researched, and high-consideration (bespoke furniture, specialist equipment, luxury goods, professional services bundled with products), text search ads allow you to communicate the value proposition, guarantee, and differentiator in ways that a product image and price cannot.
Service elements within an e-commerce business: Installation, customisation, financing, or warranty messaging is handled better in text ad copy than in a Shopping feed.
Categories where Shopping inventory is expensive and competitive: In some categories, Shopping CPCs have risen to levels where the economics only work for large retailers with high conversion rates and strong margins. Bespoke search campaigns targeting specific long-tail queries can find more efficient traffic in these categories.
Brand defence: Branded search campaigns ("your brand name + product") are more controllable via search ads than Shopping, where competitors may appear in Shopping results for your brand terms.
Queries where Shopping ads rarely appear: Certain query types, including informational queries, comparison queries ("brand A vs brand B"), and review queries ("best X under £100"), tend to trigger fewer Shopping results and are better captured by search ads.
How Should You Structure Shopping and Search Campaigns Together?
For most e-commerce businesses, the highest-performing Google Ads accounts use both Shopping and search in a complementary structure rather than choosing one over the other.
Shopping as your primary reach channel: Use Shopping campaigns (or Performance Max for product-focussed campaigns) as the primary traffic driver for product discovery. Optimise your Merchant Centre feed relentlessly for title, description, and attribute completeness. Use negative keywords at the campaign level to exclude irrelevant traffic.
Search for high-value category and brand terms: Use standard search campaigns to target specific high-value category keywords and branded searches. These campaigns give you control over messaging and allow you to test different value propositions.
Remarketing across both: Both Shopping and search support remarketing audience layers. Apply remarketing audiences to your campaigns to bid more aggressively for previous visitors, cart abandoners, and existing customers who are higher-intent signals.
How Do You Measure ROI for Each Format?
Compare Shopping and search ad performance using the same metrics, applied to comparable product and query segments:
Return on ad spend (ROAS): Revenue divided by ad spend. A ROAS of 5 means £5 of revenue for every £1 spent. Compare ROAS between Shopping and search for the same product categories where both formats are running.
Cost per conversion: Total ad spend divided by number of conversions (purchases). For Shopping, this is typically lower for commodity products. For search, it may be lower for considered purchases where intent is higher.
Assisted conversions: Shopping clicks often occur early in the purchase journey, with the actual conversion coming via a later session (direct or search). Check Google Analytics 4's attribution reports to understand whether Shopping is contributing to conversions that the last-click model attributes to other channels.
Impression share: How often your ads appear relative to the total eligible impressions. Low Shopping impression share on your core products suggests feed quality issues or bid levels that are too low for your category competitiveness.
The most reliable approach is to run both formats for the same product category with equivalent budgets for 30 days and compare ROAS directly. Let the data guide your allocation rather than making a priori assumptions about which format is better.
Dynamically manages Google Shopping and search ad campaigns for UK e-commerce businesses, including feed optimisation and campaign structure. If you want to understand which format is delivering better return for your products, get in touch for a Google Ads review.
