Google Ads can be one of the fastest ways to grow an online shop, but it is also one of the easiest places to waste budget. The difference usually comes down to the basics done well: clean product data, accurate tracking, sensible bidding, and a clear plan for profit, not just traffic.

This guide explains what a good google ads agency actually does, how to judge whether they can improve your results, and what you can do in-house to make any agency work better. It is written for UK ecommerce teams who want straightforward advice and a reliable way to compare providers.

What an ecommerce Google Ads agency should do (and what it should not)

A specialist agency is not just there to “run ads”. In ecommerce, performance depends on how well campaigns connect to your product feed, your website, and your margins. A good agency will:

• Build a measurement plan that reflects revenue quality, not only conversions.
• Fix tracking so decisions are based on accurate data.
• Improve your product feed to increase eligibility and relevance in Shopping and Performance Max.
• Structure campaigns around your catalogue, seasonality, and profit goals.
• Test creative and landing pages to lift conversion rate, not just clicks.
• Report clearly with actions, not dashboards for the sake of it.

What they should not do is hide behind vague “optimisations”, push spend without a plan, or avoid discussing margins and stock. Ecommerce is operational. Ads must match what you can fulfil profitably.

When hiring an ecommerce google ads agency makes sense

Many brands start by managing Google Ads in-house. That can work, especially with a small catalogue and stable demand. An agency becomes valuable when complexity rises or when you need faster learning without expensive mistakes.

Common triggers to bring in a specialist

• You are spending enough that small improvements matter, for example several thousand pounds per month or more.
• Your catalogue is large or changes often, and feed issues keep appearing.
• You have moved to Performance Max and results feel unpredictable.
• You are expanding into new UK regions or internationally and need a structured approach.
• You need better tracking, attribution, or consent mode support.
• Your team is stretched and cannot maintain testing and optimisation.

If your site conversion rate is very low, or your product margins are thin, an agency can still help, but you should expect them to talk about website and pricing issues too. If they only talk about bids and keywords, that is a warning sign.

Core campaign types for ecommerce (and how an agency should use them)

Google Ads for ecommerce is not one campaign. It is a system. A strong agency will choose campaign types based on your catalogue, brand demand, and the stage of growth you are in.

Performance Max for retail

Performance Max can drive scale because it uses your product feed across Shopping placements and other inventory. It can also waste budget if your feed is messy or your conversion tracking is wrong.

What good looks like:

• Clear segmentation, for example by category, margin band, or best sellers.
• Strong asset groups with relevant creative and messaging.
• Search term insights reviewed regularly to spot poor matching and brand cannibalisation.
• Use of audience signals as a starting point, not a crutch.

Standard Shopping (where it still fits)

Standard Shopping can still be useful when you want more direct control, especially for testing feed improvements or isolating product groups. Some agencies use it alongside Performance Max to keep visibility on query level performance and to manage priorities.

Search campaigns for high intent and brand protection

Search remains important for:

• Brand terms, to protect against competitors and control messaging.
• High intent non brand terms, especially for categories with clear demand.
• Promotions and seasonal pushes where messaging matters.

A good agency will avoid building huge keyword lists that never get traffic. They will focus on intent, match types, and landing pages that convert.

Remarketing and customer lists

Remarketing is not just “follow people around”. It should reflect customer value and time to purchase. Expect an agency to use:

• Dynamic remarketing based on product views and basket activity.
• Customer Match lists, for example past purchasers, high value customers, and lapsed buyers.
• Exclusions to reduce wasted spend, such as excluding recent purchasers from acquisition campaigns where appropriate.

Tracking and measurement: the part most agencies get wrong

If tracking is wrong, everything else becomes guesswork. In the UK and EU context, consent and data loss can also distort performance. A capable agency should be comfortable discussing the full measurement setup.

Minimum tracking checklist

• Google Ads conversion tracking set up properly, not only imported from analytics.
• Enhanced conversions configured to improve match quality.
• GA4 set up with clean events and consistent naming.
• Consent mode implemented where relevant, aligned with your cookie banner.
• Revenue accuracy checked against your ecommerce platform reports.

Ask how they validate tracking. A serious answer includes test purchases, tag debugging, and regular checks after site updates.

What to report on (beyond ROAS)

ROAS can be useful, but it can also mislead. A good agency will discuss:

• Profit or contribution margin where possible, especially if you have varied margins.
• New customer rate and how acquisition is separated from retention.
• Blended performance across channels, so Google Ads is not judged in isolation.
• Incrementality where practical, using tests or holdouts.

Product feed quality: your hidden advantage

For most ecommerce accounts, the product feed is the lever that improves results without increasing spend. Your agency should treat Merchant Centre as a core part of the job, not an afterthought.

Feed improvements that usually move the needle

• Titles that include the key attributes shoppers use, such as brand, product type, size, colour, and model.
• Descriptions that support relevance without stuffing.
• Correct GTINs and identifiers to improve matching.
• Product types and custom labels to segment by margin, seasonality, price band, or best seller status.
• High quality images that meet policy and show the product clearly.
• Accurate availability and shipping to reduce disapprovals and poor user experience.

If an agency never mentions feed rules, supplemental feeds, or Merchant Centre diagnostics, they are unlikely to be strong in ecommerce.

Budgeting and bidding: how to avoid wasting spend

Most wasted budget comes from unclear goals. Before you change bids, you need to know what you are aiming for and what constraints you have.

Set targets that reflect reality

• Start with break even ROAS based on gross margin and costs.
• Adjust by category if margins vary.
• Factor in repeat purchase if you have strong retention, but be conservative.

How a good agency approaches bidding

In many ecommerce accounts, smart bidding works well once conversion tracking is solid and there is enough data. The key is choosing the right strategy for your stage:

• Early stage accounts may need time to gather data before aggressive targets.
• Scaling accounts often benefit from value based bidding with sensible guardrails.
• Seasonal peaks require planning, not last minute target changes.

Ask how they handle learning periods and volatility. If they promise stable results immediately after major changes, be cautious.

Account structure: what “good” looks like in practice

There is no single perfect structure, but there are patterns that tend to work. A strong agency will be able to explain why they structure your account a certain way.

Common segmentation approaches

• By category when products have different intent and seasonality.
• By margin band when profitability varies widely.
• By price point when conversion rate and competition differ.
• By hero products to give best sellers dedicated budget and creative.

They should also have a plan for exclusions, such as excluding low stock items, poor margin products, or products with high return rates if that data is available.

Landing pages and onsite conversion: the agency should care

Google Ads performance is tied to your website experience. Even small improvements can reduce your cost per acquisition without changing campaigns.

Onsite checks that often improve conversion rate

• Mobile speed and stability, especially on product pages and checkout.
• Clear delivery and returns information visible before checkout.
• Trust signals such as reviews, payment options, and security cues.
• Product page clarity with sizing, specifications, and strong imagery.
• Fewer checkout distractions and fewer form fields.

An agency does not need to build your site, but they should flag issues, prioritise fixes, and measure the impact.

How to choose the right agency: a simple evaluation framework

Most agencies can talk confidently. Your job is to find the ones with a method, strong fundamentals, and clear communication. Use this framework to compare options.

1) Evidence of ecommerce experience

• Ask for examples of accounts with similar catalogue size, price point, and buying cycle.
• Look for experience with Merchant Centre and feed management, not only Search.

2) A clear audit approach

A proper audit should cover tracking, feed health, campaign structure, search terms, and budget allocation. It should also highlight what they would change in the first 30 days and why.

3) Transparency on fees and ownership

• Confirm you own the Google Ads account and Merchant Centre.
• Understand management fees, minimum terms, and what is included.
• Ask how often you will speak and who your day to day contact is.

4) Reporting that helps you make decisions

Good reporting is simple and consistent. It should answer:

• What changed since last period?
• What did we learn?
• What are we doing next?
• What do you need from us?

5) A plan for testing

Ask how they run tests. You want a steady rhythm of experiments across feed, creative, landing pages, and bidding. If there is no testing plan, improvement will be slow.

Questions to ask before you hire

• How will you improve our product feed? Ask for specific examples, not general statements.
• How do you validate tracking and revenue accuracy?
• How do you handle Performance Max control and brand traffic?
• How do you decide budget allocation across campaigns?
• What does the first 90 days look like? You want a phased plan.
• How do you communicate? Frequency, format, and who attends calls.

What to expect in the first 30, 60, and 90 days

First 30 days: foundations

• Tracking audit and fixes.
• Merchant Centre review and feed diagnostics.
• Campaign and search term review to stop obvious waste.
• Agreement on targets and reporting format.

Days 31 to 60: restructuring and testing

• Campaign structure improvements based on categories, margins, or best sellers.
• Feed enhancements rolled out in a controlled way.
• Creative and messaging tests, especially for promotions and seasonal angles.

Days 61 to 90: scaling what works

• Budget shifts towards profitable segments.
• Bidding strategy refinements based on cleaner data.
• Landing page recommendations informed by performance.

Results can improve earlier, but meaningful progress often comes after the foundations are fixed and enough data has been collected.

FAQ

How much does an ecommerce Google Ads agency cost in the UK?

Pricing varies by spend level and scope. Many agencies charge a monthly retainer, a percentage of ad spend, or a hybrid. The key is to confirm what is included, such as feed work, creative support, and landing page testing, and whether there are minimum contract terms.

Should we run Performance Max only, or keep Search and Shopping too?

It depends on your catalogue, brand demand, and need for control. Performance Max can be a strong core, but many ecommerce accounts still benefit from dedicated Search campaigns for brand protection and high intent queries, plus additional structures to manage product priorities.

What ROAS should we target?

Start with your break even point based on gross margin and costs, then adjust by category. If you have repeat purchase behaviour, you can set different targets for new customer acquisition versus returning customers, but keep assumptions realistic.

How do we know if tracking is accurate?

Compare Google Ads revenue to your ecommerce platform over the same period, allowing for attribution differences. A good agency will also run test orders, check tags in a debugger, and confirm that key events fire correctly across devices and browsers.

How long does it take to see results after switching agencies?

Some quick wins can appear in the first few weeks, especially if there is obvious waste or feed issues. More reliable improvements often take 6 to 12 weeks because changes need time to learn and because ecommerce performance is influenced by stock, pricing, and seasonality.

Do we need to give an agency access to our Merchant Centre?

Yes, if you want them to manage Shopping and Performance Max properly. Merchant Centre is where feed health, policy issues, shipping settings, and product approvals live. Without access, an agency cannot fix many of the root causes of poor performance.

Final checklist: choosing the right partner

• They can explain how they will improve tracking, feed quality, and campaign structure.
• They talk about profit, stock, and operations, not just clicks and impressions.
• They provide clear reporting with actions and priorities.
• You own your accounts and data.
• They have a realistic 90 day plan with testing built in.

If you use this checklist for choosing an Ecommerce Google Ads Agency, you will be able to choose an agency based on substance rather than sales talk, and you will set your Google Ads account up for steady, measurable growth.