How to Choose a CRO Agency: Picking the Right One for Your Business

We’ve had a few calls over the years that start with a situation a lot of people feel a bit awkward about. It starts like this:

“We’ve already paid another agency for a CRO audit, but we still don’t really know what to do next.”

The previous agency may have delivered heatmaps, screenshots, a long audit deck and a list of recommendations. But it didn’t actually translate to a working CRO programme; sometimes the work wasn’t actually appropriate to the store’s traffic mix, sometimes it doesn’t factor in margin or the buying journey. And sometimes it’s wildly out of sync with the brand’s internal capacity, Shopify setup or commercial goals.

We usually start with the good news here: “It’s not a you problem.” See, none of those factors is moveable - you can’t change them. So your CRO agency needs to be able to work with them.

And this is where choosing the right CRO agency becomes a bigger decision than it first appears.

A CRO agency can help you turn more of your existing visitors into customers. A good one should also help you understand which parts of the site are holding back revenue:

• the product page that that isn’t showing delivery information

• the mobile menu that makes browsers guess where to find products

• an accordion that hides subscription benefits

• or the cart drawer that completely misses the opportunity for upsells and crossells

A poor fit (or just a poor agency - and they are out there) can do the opposite. It can burn time, create a messy backlog, straight up confuse you, and leave you with changes that sound like good ideas in isolation but do little for conversion rate, average order value or repeat purchase.

More good news: all that is completely avoidable. If you know what to look for. And because that’s a complete where-do-I-start minefield, we’ve done all the work for you. Here’s how to choose a CRO agency that will feel good and get the results you want.

Start with the Agency’s Specialism

The first question…

Does this Agency Work in Your World?

CRO for a SaaS sign-up flow, a B2B lead form and a Shopify Plus store are related, but they are not the same job. Architects who specialise in designing school buildings won’t just try and turn their hand to luxury skyscrapers because they get a lead for one.

An ecommerce CRO agency needs to understand product discovery, product detail pages, collection pages, cart behaviour, payment options, delivery clarity, returns, subscriptions, reviews, discounts, bundles, mobile UX, paid traffic and repeat purchase. Actually, they need to be experts in all of them; really you want them to have seen it all.

If you run a Shopify store, ask directly how much of the agency’s work is Shopify or Shopify Plus. A generalist digital agency may have smart people, but you need to know whether they understand Shopify’s theme structure, checkout limits, app stack issues, analytics quirks and the reality of getting changes shipped without breaking something during a sales period. This stuff is highly specific and is what makes the difference to you.

For example, at Blend, our Shopify CRO work is built around existing ecommerce traffic, structured testing and implementation, with all design and development work. That focus matters because CRO recommendations only become useful when they can be built, tested, measured and rolled out properly, following the vision of the CRO strategy.

A next question to ask:

“What type of CRO work do you do most often, and what type of work do you avoid?”

That second half is really worth including. Top CRO agencies tend to know where they are strong. If an agency claims to handle every platform, every sector, every business size and every growth problem with equal depth, keep digging.

Look at Their History

How long have they been doing CRO? Did they begin as a design agency, a development agency, a paid media agency, an analytics consultancy, or a pure experimentation team? None of these is automatically better. The origin story can tell you how the agency sees problems.

A design-led team may spot visual and UX issues quickly. A development-led team may be strong at implementation. An analytics-led team will be excellent at measurement (you hope!). The stronger agencies have usually built a mixed team over time: strategy, UX, analytics, development, QA and project management (because everything falls apart if it’s not following a plan).

Blend started in Shopify development before becoming a specialist CRO agency, and that shapes how we think about implementation. A recommendation has to survive contact with the theme, the app stack, the data setup, the customer journey and the client’s internal capacity.

When you research a CRO agency, look for signs that their process has matured. Do they explain how they gather data? Do they show how they prioritise work? Do they have a clear view on when to test and when to implement? Do they publish their thinking, and does it go beyond generic “increase conversions” advice? What do they measure, and what do they consider the most important metrics?

Further reading: See our article on when to A/B test vs implement CRO changes - this is one of the places where an agency's CRO philosophy shows up. Testing everything sounds disciplined until your roadmap becomes enormous and painfully slow. And just implementing without validation is very obviously risky, at best.

Match Their Clients to Your Store’s Stage

Client logos can be useful, but only if you know what you are looking for. It’s definitely a good thing to see clients that look you, but that’s not always the be-all and end-all.

Equally a CRO agency may have worked with impressive brands, but your store might need a different type of support. A seven-figure Shopify brand with a small internal team has different needs from a large Shopify Plus brand with in-house developers, a trading team and a paid media agency sending daily requests. And sure, they might have worked with Nike, but 1) did building a microsite for HR really count? And 2) there probably isn’t all that much you can learn from Nike.

Look at the types of clients the agency has worked with:

• Are they ecommerce brands or mostly lead generation businesses?

• Are they used to DTC, retail, subscription, high-ticket, food and drink, beauty, wellness, pet, automotive, fashion or technical products?

• Have they worked with stores where mobile drives most sessions?

• Have they dealt with Shopify subscriptions, bundles, product finders, Recharge, Rebuy, quiz flows or complicated variant logic?

• Do their case studies show similar buying decisions to yours?

The best comparison isn’t always “same industry, same product”. It’s more like “same kind of customer decision”.

A coffee subscription brand and a pet food subscription brand can actually have more CRO overlap than two brands in the same broad retail category. After all, what even is “fashion”? Both need to help customers choose the right product, understand frequency, trust the subscription terms, and feel comfortable that changing or cancelling will not be a pain. The value you’ll get from your CRO agency should be in their understanding of and insight into your customer - not 50 other brands that superficially look a bit like you.

Being frank, part of the reason we work so hard to stay up-to-date with our case studies and publish our A/B test library (almost 100 tests) is because we want brands to see and understand the depth of our thinking. Have a look and you’ll see each test write-up shows you the page, the test idea, the result and the commercial context. When reviewing any CRO agency, look for that level of detail. There should be work they want to shout about.

Read Results with a Commercial Eye

A headline conversion rate uplift can sound impressive, but it may not tell the full story. If conversion rate increased because the site ran heavier discounts, pushed low-margin products, or changed traffic mix, the business may not be healthier.

Ask how the agency measures success beyond conversion rate. For ecommerce, useful metrics often include:

• Revenue per session (the ultimate, in our view)

• Revenue per visitor

• Average order value

• Add-to-cart rate

• Checkout completion rate

• Subscription adoption

• Repeat purchase rate

• Customer lifetime value

• Margin impact

• New vs returning customer behaviour

Our guide to key CRO metrics and how to calculate them helps explain how these numbers relate to one another.

When reviewing results, ask what changed on the site. A strong CRO case study should show where the change happened: homepage, collection page, PDP, cart, checkout, navigation, search, quiz, subscription widget, payment area or post-purchase journey.

“We improved conversion rate by 20%” is less useful than:

“We moved sizing guidance closer to the add-to-cart button on mobile PDPs, clarified delivery cut-offs above the fold, and tested a sticky CTA for returning visitors. Conversion rate improved, and revenue per visitor increased without reducing AOV.”

That level of detail shows the agency can connect customer behaviour to page-level changes.

Check Their Reviews for Working Style (Not Just Praise)

Reviews are useful, but read them like you would read product reviews on your own store - in other words, scrutinise the quality of the review, not just the quantitative aspect.

A five-star rating is a nice box checked. The text underneath is the really interesting bit.

Look for comments about communication, clarity, delivery, technical quality, project management, responsiveness and whether the client felt more confident making decisions. See if team members are named. CRO work can involve research, awkward truths, failed tests, urgent fixes, competing opinions and a fair bit of “we thought this would work, but the data says otherwise”.

That means the relationship has to function properly.

Of course, we’ve got our own reviews page and it’s useful social proof, but the same logic applies to any agency you’re researching. Look for reviews that explain what the agency was like to work with, not just whether the client liked the final result.

A few useful questions:

• Did the agency explain the work clearly?

• Did they challenge the client when needed?

• Did they deliver what they said they would deliver?

• Did they handle technical details carefully?

• Did the client mention speed, clarity or accountability?

Bear this is mind when they’re pitching, too. A CRO agency that communicates poorly during the sales process is unlikely to become magically better once the work starts.

Treat Awards as a Positive Signal - in Context

Awards are not everything. But they are still a useful signal.

What an award can tell you: they definitely do some good work, external judges have reviewed it, along with results, methodology and probably client comments, and they’re organised and conscientious enough to put together a good awards entry in the first place. That is worth factoring in alongside case studies, reviews and your own conversations.

What awards won’t tell you: whether an agency is right for your store, budget, team or current problem.

We’ve written about winning Global CRO Agency of the Year 2026, and we’ve also shared more about our multi-award-winning CRO and ecommerce agency work. What we wanted to do with those posts was actually give some substance to the wins, and share some detail on the work that won us awards, rather than just waving around a gong and hoping someone claps (not that we’re above enjoying that).

When you’re looking at agency’s awards, ask:

• What was the award for?

• Who judged it?

• Was it based on results, process, client work or agency growth?

• Does the award connect to the service you need?

• Can the agency show the client work behind the recognition?

Also bear in mind specificity: a CRO award is more relevant than a broad marketing award if you are choosing a CRO agency. A Shopify-related award is more relevant again if your store is built on Shopify.

What to Look for in a Digital Agency that Offers CRO

If you’ve not worked with a CRO agency before, it can be daunting feeling like you’re grilling someone who knows more about the thing than you. But you can still ask informed questions that are fair. This is particularly worthwhile if you’re weighing up specialist CRO agencies against development or full-service agencies that also offer CRO - if you don’t get a straight answer to any of these questions, it tells you something about their level of specialism.

A good CRO partner should be able to explain:

• How they collect quantitative data

• How they review qualitative behaviour

• How they form hypotheses

• How they decide what to test

• How they decide what to implement without testing

• How they measure impact

• How they document learnings

• How they hand work over to your team

• How they handle QA before changes go live

You should also ask who will actually do the work. Senior people on the sales call are useful, but you need to know who will review your analytics, inspect your PDPs, design variants, write test plans, build changes, QA updates and report back.

The handover between strategy and implementation is also where a lot of CRO work falls short. A strategist spots the issue, a designer interprets it, a developer builds something close to it, and then the final version goes live without the original reason being properly preserved.

Look for team structure that’s designed to avoid this.

If you have an internal development team, you may only need an audit, roadmap and guidance. If you don’t have dev resource, or you’re stretched, then you’ll probably need the agency to handle design, development, testing and QA.

We offer different delivery routes through CRO audits and ongoing CRO implementation, because the right setup depends on the client’s capacity.

How Much Research Should You Do?

For a serious CRO retainer, research three to five agencies before making a decision. You don’t need a giant spreadsheet with 47 weighted columns, and you’re better off writing your own brief with some careful thought than getting ChatGPT to do it before you (and believe me, every agency you contact will spot an AI-written brief a mile off).

A feasible process for researching the right CRO agency can be:

1. Read the agency’s service pages

2. Review at least three case studies or A/B test examples

3. Check reviews and testimonials

4. Look at the agency’s blog, LinkedIn presence and recent content

5. Look into the people behind the agency and get a feel for their culture, history, way of doing things and reason for being

6. Ask how they would approach your store based on traffic, revenue, AOV, margin and team capacity

7. Ask who will actually do the work

8. Compare proposals based on fit, depth and delivery model, not just price

If your store has enough traffic for regular A/B testing (>50,000 sessions a month is what we recommend), ask how they judge test validity. If your traffic is lower, ask how they balance research, implementation and measurement without pretending every change can be tested to statistical confidence.

Below that 50,000/month mark CRO can still be valuable, but the work may lean more toward audit, evidence-led implementation, UX fixes and careful before-and-after measurement - A/B testing shouldn’t be part of the CRO engine.

Questions to Ask before Choosing a CRO Agency

Use the call with the agency to test how they think. After all, you’re hiring brains.

Ask questions such as:

• What would stop you from recommending an A/B test?

• What data access would you need before giving recommendations?

• How do you prioritise CRO work when there are 30 possible changes?

• How do you measure success beyond conversion rate?

• What happens when a test loses?

• How do you handle development and QA?

• Who will be on our account after the sales process?

• What would you need from our team to make the work successful?

• How do you work with paid media, email and retention teams?

• Can you show an example where the insight, page change and result are clearly connected?

• Do you do strategy only, or do you handle implementation too?

• [If yes] Are your developers all in-house?

Pay attention to how specific the answers are.

A less-than-satisfactory answer stays at the level of “we use data and best practice”. A good answer mentions funnel reports, product page behaviour, mobile recordings, checkout progression, search usage, subscription selection, PDP layout, test design, QA steps and reporting cadence.

Red Flags when Choosing a CRO Agency

You can usually spot warning signs early when you’re in discussions.

Be cautious if an agency:

• Guarantees a conversion rate uplift (they cannot guarantee anything - they are saying what they think you want to hear to try and make a sale. Run a mile.)

• Talks mainly about best practices without asking for data

• Focuses only on conversion rate, ignoring AOV, margin, retention or revenue per visitor

• Cannot explain how recommendations become live changes

• Has no clear view on testing validity

• Shows results without showing what changed

• Avoids talking about failed tests

• Has vague processes for strategy, design and development

A good CRO agency should be comfortable saying, “We don’t know yet.” If you want to know exactly what’s holding you back, that is frankly the only right answer. They should then explain what they need to review before giving a proper answer. Again, if they claim to have all the answers before you’ve paid them for any work, they’re just not being honest, or they’re at best naive.

Being a Good Client Helps You Choose Better

The way you run the selection process affects the quality of advice you receive.

If you want agencies to give useful recommendations, give them useful context. Share your store URL obviously, along with current challenges, traffic level, AOV, main markets, paid media reliance, internal team setup and any constraints around theme, apps, stock, margin or brand rules.

You don’t have to give away every commercial detail on the first call, but vague inputs usually create vague proposals and you won’t like what you get.

There is also a point about basic respect here. If an agency has spent time reviewing your store, joining calls and preparing a proposal, reply to them. Even if the answer is no. Actually, especially if the answer is no.

Doesn’t have to be a dramatic breakup message. Something simple is fine:

“Thanks for the time you put into this. We’ve decided to go with another agency because they had more experience in our industry/met our budget constraints/we liked their hair better. We appreciated your input.”

Don’t feel you need to add fluff like “They’re a closer fit for our current internal setup,” or “We’ve gone in a different direction.” No one will know what that means and it won’t help anyone. Just speak plainly and tell the truth. Doing anything other than that is discourteous.

If the agency asks who you chose, it’s fine to tell them. They may well know the outfit you’ve chosen, they’ll understand the decision, and they can use the feedback to improve their own process. As for the agency you’ve gone with - it’s very unlikely they’ll be weird about you telling their competitors they’ve won you as a client. They’ll probably want to shout about it themselves anyway. No, of course, don’t go sharing fine details of pricing or giving away anything confidential, but there’s nothing wrong with answering the polite question “Who did you go with?”

Above all, don’t just disappear. Ghosting wastes time and leaves people guessing. It also makes future conversations awkward if you come back six months later after the chosen agency did not work out. Which happens. Far more often than people admit.

Finally, don’t underestimate the damage ghosting can do to your own reputation, both for your brand and personally. Agencies talk to each other, staff move around agencies, and word about timewasters spreads quickly.

It’s simple: treat agencies with the same respect and courtesy you expect to be treated with.

Choosing the Right CRO Agency for Your Business

The right CRO agency should fit your store’s stage, platform, traffic level, internal capacity and commercial goals.

If you need to understand what’s stopping visitors from buying, start with a detailed CRO audit. If you already have a clear roadmap but no time to build and test changes, look for CRO implementation support. If your site has strong traffic and enough transactions, choose an agency that can run a structured testing programme and explain what happens when tests win, lose or come back flat.

When people search for top CRO agencies, they often end up comparing names, awards and client logos. Those are all useful, but they don’t actually tell you exactly what they can do for you, who they are and what they’re really like to work with. The specific question that will help you find the right CRO agency for you is:

“Which CRO agency can look at our Shopify store, understand how our customers buy, work with our team, and turn evidence into changes that improve revenue without creating chaos?”

That’s the CRO agency you want.