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What is Conversion Rate Optimisation (CRO) All About?

February 22, 2019

What is CRO?

Ok, so firstly let’s clear up the meaning. CRO is the practice of incrementally increasing the opportunity or the rate at which your website visitors convert to a response action. This means we turn the simple visitor into an actual buyer on an e-commerce site or a serious enquirer on a service website.

So let’s cover, why this is done, how this is done, what you currently could be doing wrong on your website and what the benefits are of working with an agency that offers Conversion Rate Optimisation as a service.

Why is CRO important?

Well, this bit is quite simple. Most of the clients we engage with want to grow their business, let’s be honest, that why most people are in business. So one way to do that is to get more customers and sell more stuff right?

We’ve seen a trend in business growth between the number of visitors you bring to a website through the many digital marketing practices, SEO, PPC, social media marketing, digital PR etc, we’ve seen this in our business, but that will only get you so far. Your visitors may be coming to your site because your SEO is strong or your PPC campaigns are spot on, but it’s very possible, in fact, it’s likely, that you’re missing out on converting some of these visitors into actual customers for one reason or another.

How do you implement CRO?

Quite simply, small or incremental changes as I mentioned before are done to a specific piece of a page of your website, that is then tested (or split tested as we call it) against the original page to see which gets better results.

Let me put this into a simple example to demonstrate:

You have a product page (see image below). You currently bring 100 people to your website and you sell on average 3 products for every 100 visitors that you bring to your website. This is typically in line with Google’s suggested 5% conversion rate.

You want to increase your conversion rate as selling more product will help you grow your business.

Split Testing

So, an agency like us creates a scenario (this word is important so please remember it). We build you an identical page but this time, not with a blue ‘BUY NOW’ button but with an orange one. This is because we know that an orange button is 32.5% more likely to convert than any other colour button. So now we have 2 of the same pages with different coloured buttons. We serve 50% of your next 100 visitors with TEST-PAGE-A, the original blue button, and we serve the other 50% of the next 100 visitors with TEST-PAGE-B, the one with the new orange button. This is called A/B split testing.

Now one of three things will happen:

  1. The test will prove that the orange button converts better. 2 people bought from a blue button and 7 bought from an orange button. RESULT!! We roll out TEST PAGE B to every new visitor after this point and that as a test is complete and we are confident that your original 3% conversion rate will be improved upon going forward. Next steps… Invent more scenarios to test.
  2. The test will prove that our assumptions were wrong and the original blue button was better than we thought. STILL A RESULT!! Because we now know that this is the best for conversion out of the two. Next steps… Invent more scenarios to test.
  3. The test was inconclusive and let’s say that 49% of people bought from a blue button and 51% bought from an orange button%. This metric is neither here nor there as we are looking for better results than this. Next steps… Invent more scenarios to test.

AB Testing

What Might Not Help My Current Conversion Rate?

There is a multitude of reasons, literally thousands why your website may not be converting as well as it could be. These range from simple colours of buttons as we’ve mentioned above to page length, poor copy, lack of product descriptions, slow loading times, poor quality images, poor user experience, poor page layout, the list goes on.

Why Use an Agency for CRO?


Agencies have done hundreds of test and an agency will have a range of experts with a really good understanding of design, UX, content, development and ultimately what practices can help convert your visitors. CRO is not just about making a change, it’s about great design, it’s about consideration of your audience, it’s about the user journey, its about colour, space, words, messaging, typography… the list goes on and on and agencies have all this knowledge behind them to use to your advantage.


Using an agency to implement your CRO can be really beneficial. Think about it. The agency is running dozens of tests at a time of a range of clients in a variety of sectors and what they learn from one client they can quickly implement into another clients website giving exceptional value for money. Best practice changes every day, the way we react to things online changes all the time, so using an agency that has their finger on the pulse can be a fast track to online success and potentially save you money.


You paying the agency on a retainer to look after your CRO, develop new scenarios and constantly test/measure, test/measure so they will be all over it day by day. If they see a scenario taking a drastic turn for the worse, they can quickly roll back to the original solution, then go again with a new scenario.

At Fifteen, we have years of experience implementing CRO techniques. From the niche to the obvious, we can help you improve your site’s performance. For more information or to get started on improving your site, contact us today and watch your metrics soar.




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