Team climbing, symbolizing the right team and cro expert


Your decision is made. After years spending on trafic acquisition, now it's time to optimize for conversions. And you got a budget for that... Wise move ! 

To get started on the right foot, you want to bring in an external expertise, by hiring a CRO consultant.

A perfect match within your budget is never easy to find.

That's why, even if you're new to CRO, I wrote a list of 13 questions that will avoid you to hire the wrong guy.

1) What's your market and niche ?

Common answer : every website with any goal

A good answer would be more specific and closer to your business like the same industry or the same business model.

Examples : Classified ads in the car industry, e-commerce, or lead generation B2B sites, Saas start-ups building mobile apps…

A CRO expert knows how to deal with any kind of website, because industries change, but the process remains the same. But if you find a skilled consultant, who is working in your industry on a regular basis, that's even better.

2) What size are your clients ? Are you focusing on SMB, mid-size or large companies?

Not the best answer : any business site, no matter the size.

Preferable answer : Specialized in small to mid  biz, OR large businesses.

It is definitely not the same work on a huge site and tiny site. The requirements are not the same, the communications are not the same, decision process… Et cetera.

The CRO consultant will ask you about the traffic, the business models, and maybe the number of people in your company, in the marketing team.

Also, the monthly traffic will determine if the site is eligible for A/B testing. For tiny sites, we just don't A/B test, and use other CRO techniques. 

If your site has millions of pageviews each month, the consultant should have a quality assurance process, ask about it. In short, testing the treatments (version B) should be deepened.

3) "So, what do we test ?"

The goal here is not to get a free list of ideas, but rather to assess the consultant's CRO skills. 

If you've never optimized for conversions before, use your common sense and marketing skills (it often boils down to it).

And, even if it's good to listen one or two great ideas, focus on the optimisation process. When we're looking at a new website, it's impossible to refrain from having an idea.

But the great optimizer goes beyond his own ideas. One must dive into the data to provide valuable ideas, that fit with the  context  of your business. 

If someone gives you ideas out of your website's context, that's basically reciting. You can find such lists all over the internet, search for "CRO best practices" in Google...

When a consultant gives you ideas for text changes, that's preferable. It means that he understand the value proposition of your business and customers' pain points. He put himself in customers' shoes, and imagine what a powerful tagline would be.

About the optimization process, here is a list of questions you may ask. While interviewing, it's good to combine open ended questions (fishing) and closed questions (shooting).

  • Phase 1 : Analysis 
    • How do you conduct a typical analysis ?
    • Which sources of data do you use ?
      All CRO consultants will mention Google analytics. A more detailed answer would include heatmaps, on-site surveys, competitors benchmarking, and maybe session recordings, user testing sessions
    • What kind of things are you looking for during Analysis ? 
      • The "Where": Areas of great potential should be looked for. Basically, web analytics provides this information.
      • The "What & Why": Heatmaps, user testing sessions and session recordings show how the visitors interact with the site. These tools give valuable ideas to enhance the user experience, and lead visitors down the conversion funnel. On-site surveys may even lead to a larger rethinking of marketing messages.
  • Ideas, hypothesis, and priorization
    • Do you provide a list of test ideas ? 
    • How do you choose your first recommendations?
      Here, you want to hear the CRO consultant talk about how he scores each idea. Like, "this idea XYZ is good, but it only affects the homepage, which only gets 5% of the traffic. So, I'm not gonna recommend that first."
    • What's the validation process ?

4) What's your communications process before launching an A/B test ?

Just check that you agree with the process offered by the consultant.

What I like to do:

  • After the analyses, I choose 5 to 7 tests which I think are the most profitable.
  • I write an email to validates of principles with the client before going further. Sometimes it implies a few visuals, but not too many at this step. Every client has his own considerations about what can't be done, this is perfectly normal.
    So, for the consultant and the client, it's important to get the client's validation ASAP, not to waste too much time into a test which will never be launched.
  • When the test is ready to be put into production, I send another email with visuals, and a link to preview the test. Upon validation, I launch the test.
  • Every week, I send screenshots of each A/B test's results to the client. This comes with recommendations about what we should do: continue, send all the traffic to the treatment, or move on to the next test.


5) What are the deliverables of your services ?

When you hire a CRO consultant, you may expect a rise in your conversion rates... But conversion rates are changing every day, just as your traffic.

You will have to smooth the data to assess how your consultant's actions have a positive impact, or not. 

The best way for you as a client to get reports, is on a Google analytics report. But let's come back to this later.

A/B testing reports

If you're doing A/B testing, it is a good thing if the consultant offers weekly reports. The reports do not need to be lengthy, but with a weekly frequency, you'll always know how tests are going.

The deliverable of a successful A/B test, is a higher performance for the treatment. If you get a nice steady curve showing you, say, a 40% uplift, then your CRO consultant fulfilled his contract.

Overall conversion rates reports:

CRO may take some time, depending on your traffic and where you start from. To get results, you and your consultant need to be consistent in your efforts.

On a monthly basis, or sometimes twice a month, check your conversion rates for your different KPIs on Google Analytics.

If you're not doing A/B testing, Google analytics will often be the only place to check results.

At best, your consultant will set up custom reports with your KPIs, and will set up an automated email for you.

6) How fast can you provide a positive uplift in conversions ?

Honestly, it's hard for any consultant to say. The must reliable way to get strong numbers, is using A/B testing.

A/B testing requires traffic, so it all depends on how much traffic you have.

It will be easier to get results, positive or negative, if your site has a lot of traffic. Because iterations will go faster.

For each test, your consultant will try to get at least a 95% confidence. In short, it means that the results are most likely reliable.

After the 5 first A/B tests, I expect at least one to be positive.

So to answer this question : How long to get an uplift ?

Use a sample size tool, and estimate how long it takes for you to get statistically valid results for one A/B test, and multiply by 5.

For example, for a given website with :

  • 3000 visitors per day,
  • 5 A/B tests running simultaneously,
  • average conversion rate : 3%
  • Assuming that all the tests affect all pages, 
  • Assuming that our treatments get at least a 30% uplift or downlift

It takes 16 days before declaring a winner or a loser, with a 95% confidence.

Try for your site with this free Excel spreadsheet calculator on VWO.

7) Authenticity : Does the person just reciting what he/she read in blogs ?

This is something you should be very careful about. Actually you can find a lot of good information about conversion rate optimisation (like this blog ;) ). 

Ensure that the consultant has experience. Ask for references, case studies of his own, and everything that can confirm this is a real expert.

At best, you should be able to see some of the portfolio of the person interviewed. Any serious consultant will protect the confidentiality of his clients. But maybe, he or she will agree to show you A/B tests from websites in other regions of the world, and in other industries.

By asking about the process, and the other questions in this post, you should be able to distinguish between an amateur and an experienced optimiser.

8) What do you optimize for ? 

Anyone would be able to list a few common goals for AB tests : Number of transactions, upsells, number of leads, sign-ups,  etc

This is an easy one, apparently.

A good answer, would mention 2 things :

  • Micro-conversions, macro-conversions and revenue shoud be clearly differenciated in the consultant's mind.
  • While optimising for ......., revenue should always be kept in mind.
  • To optimize for revenue, Google Analytics is the tool of choice to analyse the results of AB tests. It shows the version B's impact on each step of the funnel. This requires Google analytics integration with your A/B testing software.

9) What do you need from me ?

Depending on your available resources, you should hire a consultant who provides turnkey service. Or maybe you would like the consultant to work smoothly with your team (developers and web designers).

If you have very little time to dedicate to your newly hired consultant (at first at least), then ensure you choose someone with a great autonomy.

When you just hired a consultant, I recommend you to have a conversation about what you've done before, and what you want to do next. It is insightful from a consultant's point of view.

Unfortunately, most clients really don't have the time to chat, or answer questions.

In this common situation, a good consultant will analyze your data, and will come back to you with 'yes or no' validation questions. 

10) How do you ensure everything is working properly, before launching an A/B test in  production ?

If your website has millions of page views each month, you really don't want your web designed to be messed up.

A CRO specialist has a quality assurance process.

This involves trying the treatments in different browsers, or using a browser testing tool. This latter option allows you to test modifications in hundreds of browsers/OS/resolutions combinations.

Also, the consultant should ensure that everything is going well the first few hours after the launch. This is an easy spot to uncover problems.

Pro tip : Having a look at daily conversion rates. If a conversion rate suddenly falls down to zero, it's most likely a problem with the code that requires attention.

11) Let's talk about your Skills : What makes you a CRO expert ?

Conversion rate optimizers must combine very different skills. For this reason, there may come from different backgrounds.

Asking this question allows you to better know what the strengths of the consultant are. Like the following:

  • Marketing
  • Web analytics
  • coding 
  • psychology
  • creativity

If you already know what skill set you're after, it will help you making a decision.

Often, optimisers may have either a marketing background, or a more technical background. Actually, the expression "growth actor" is quite relevant for CRO optimisers.


CRO is full of opportunities, but as always, finding a skilled consultant is not easy.

Using these 11 questions, you'll be able to distinguish between a would-be optimiser and a CRO veteran.

I hope you will find the one-in-a-million consultant, who will do wonders for your website. Or you may click the button below to contact me.


What more would you ask to a consultant ? Let me know in the comments below.



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