Google Ads for ecommerce UK should be generating a return, not just traffic. Most Shopify and WooCommerce businesses running Google Ads hit the same wall: spend goes up, revenue follows to a point, then margins compress and the numbers stop making sense. That is not a Google Ads problem. It is a campaign structure problem. The right build generates 3-5x ROAS on managed spend. The wrong build generates expensive traffic that does not convert.

Three structural failures cause most ecommerce Google Ads waste.

Performance Max set and forgotten. Performance Max (PMax) campaigns are Google's default recommendation because they are easy to run and give Google's algorithm maximum control over budget allocation. For businesses with deep conversion data and well-structured feeds, PMax can perform well. For businesses just starting out, PMax will find the path of least resistance (often brand searches and YouTube views) and spend budget on traffic with weak intent. Without the right exclusions, audience signals, and product feed quality, PMax burns spend with minimal return.

No product segmentation. Running all products in a single campaign or ad group means your best-margin products and your worst-margin products compete for the same budget. A product with a 60% margin and a £40 average order value should support a higher bid and more spend than a product with a 15% margin and a £12 order value. Without segmentation, the algorithm optimises for conversion volume rather than profit. You sell more but earn less.

Shopping feed neglect. Your Google Shopping campaign is only as strong as your product feed. Missing GTINs, weak product titles, absent attributes, and incorrect categorisation all suppress impression share. Competitors with better-structured feeds appear higher and more frequently for the same searches. Feed optimisation is unglamorous work that most agencies skip. It directly affects campaign performance.

We start with a full account audit: what campaigns are running, what they are spending on at the search term level, what the actual margin contribution is by product category, and what the feed quality looks like in Google Merchant Centre.

From that audit we build a campaign architecture segmented by margin tier and product category. High-margin, high-converting products get dedicated campaigns with higher target ROAS floors. Lower-margin products run on tighter constraints or get excluded if the economics do not work at any sensible bid level.

For Shopping and PMax, we build structured product groups, clean up the feed, add the correct GTINs and attributes, and set audience signals that focus Google's algorithm on your actual customer profile rather than anyone who has ever visited your site.

Search campaigns for high-intent non-branded terms (specific product searches, competitor searches, category searches) run separately from Shopping to give you control over bid strategy by intent level.

ROAS varies substantially by category, margin, and competition. For UK ecommerce businesses with average order values above £60 and properly managed campaigns, 3-5x ROAS on Shopping spend is achievable in most competitive categories. Fashion, health supplements, and home goods typically fall in this range. High-competition categories like electronics or commodity goods run tighter.

The more important metric than ROAS is contribution margin per £1 of ad spend. We help you calculate that number and work backwards to the ROAS target that actually makes sense for your business, not an industry benchmark that ignores your cost structure.