A conversion rate optimisation agency promises more sales from the visitors you already have. For a big online shop, that can pay for itself many times over. For a coach or small business with modest traffic, it often can't, because the testing at the heart of classic CRO needs volume you don't have yet. Here is what these agencies do, what they cost, and what to do instead.
A conversion rate optimisation agency researches why visitors don't buy, then runs A/B tests to fix it. Retainers commonly run from the low to the high thousands a month. It's worth it when you have thousands of visitors and steady sales each month. With less traffic, fixing the offer, page clarity and follow-up usually wins more.
Who this is for: Coaches, consultants and small business owners wondering whether to pay a CRO agency to lift their sales.
A CRO agency works out why people land on your site and leave without buying, booking or signing up. Then it changes things and measures whether the change helped. The work usually follows the same loop, whoever you hire.
Some agencies also handle the design and build of new pages, while others hand you the plans and leave the build to your team. Ask which one you're paying for before you sign.
Done well, this is careful and useful work. It takes guesswork out of changes on a busy site. The catch is in step four, and it matters a lot for smaller businesses.
This is the question most agency pages skip. An A/B test only tells you something true when each version gets enough visitors and enough conversions. Without that, the "winner" is often just luck, and you end up making changes based on noise.
As a rough guide, reliable tests tend to need thousands of visitors to the page and a decent number of conversions for each version, every few weeks. A large online shop has that easily. A coach getting a few hundred visitors and a handful of bookings a month does not. A test on that site could run for months and still not give a clear answer.
So the honest picture is this. If you sell a lot online and traffic is steady, classic CRO can be very good value. If you are small, button colours and headline tweaks are the wrong place to spend money. Your bigger wins sit in the offer itself, how clear the page is, and what happens before and after someone lands on it. Our guide on how to increase your conversion rate goes through those in order.
Most CRO agencies charge a monthly retainer, commonly somewhere in the low to high thousands a month at the time of writing, depending on how many tests they run and how much design and build is included. Many also sell a one-off audit as a fixed project, which is cheaper and gives you a prioritised list of fixes. Some tie part of the fee to results, though that is less common.
Here is how the main routes compare.
| Option | What you get | Traffic you need | Typical cost | Best for |
|---|---|---|---|---|
| CRO agency | Research, ongoing A/B tests, implementation | High: thousands of visitors and steady conversions a month | Monthly retainer, commonly low to high thousands | Busy online shops and software with real volume |
| CRO audit or one-off review | A report of problems and a ranked fix list | Any, though more data helps | One-off project fee | Owners who can make the changes themselves |
| Done-for-you marketing studio | Fixes the offer, pages, email and follow-up, then runs it | Any | Varies, usually quoted after a review | Small businesses whose whole path leaks, not one page |
| DIY | Free tools, your own time and judgement | Any | Your time plus low-cost tools | Early businesses with more time than budget |
Whichever route you pick, ask what you'll have at the end of the first three months. A clear answer, in plain words, is a good sign. A vague promise of "learnings" is not.
When you can't test your way to an answer, you fix the things that are clearly broken. These rarely need a test to prove them, because the problem is visible once you look.
Watch a dozen session recordings before changing anything. You'll often spot the problem in an afternoon. Then rebuild the page using the basics of a high-converting landing page.
Hold off on a CRO agency if you get a few hundred visitors a month, if you're still changing what you sell, or if most of your sales happen on calls rather than on the page. In those cases an agency will either run tests that never reach an answer, or quietly do general fixes at testing prices. Put the money into traffic and a clearer offer first.
You also don't need anyone if you have the time to work through the list above yourself. Plenty of owners double their results that way, and we'd rather you did that than paid for help you don't need.
A done-for-you studio fits a different problem. When the leak isn't one page but the whole path, from the post that brings someone in to the email that should have followed up, testing buttons won't fix it. That's the work we do at Unbury: find where customers are slipping away, build the fix across the offer, pages, email and follow-up, and run it week to week. If you're not sure which problem you have, start with a free audit and we'll tell you honestly.
A CRO agency focuses on turning more of your existing visitors into customers, mainly through research and testing. A marketing agency usually focuses on bringing more people in through ads, content or social media. Some studios do both, fixing the path from first click to sale.
Most agencies spend the first month or so on research before testing anything. Each test then needs enough traffic to give a reliable answer, which can take weeks on a busy site and much longer on a small one. Expect a few months before you can judge whether it's paying off.
It can be, if you are able to make the changes yourself afterwards. A good audit gives you a short, ranked list of fixes based on your analytics and real visitor behaviour. Ask to see an example report before you pay, so you know it will be specific to you.
Yes, and for a low-traffic business it's often the sensible place to start. Install a free tool like Microsoft Clarity, watch how visitors use your key page, and fix what's clearly broken. Tighten the offer, use one call to action and reply to new leads quickly.
Send us your setup and we will tell you honestly where it is leaking customers and what to fix first. Free, no pitch.