Conversion Rate Optimisation v Search Engine Optimisation

by David Mannheim

posted on: December 29th 2015

When describing what CRO is to the new, we tend to describe it as simply as possible and usually in relation to SEO; framing a new concept to a known concept and relating the two in a form of conditioning. This is how we do it:

[blockquote color="#a5d2d0" bordercolor="#a5d2d0" author="User Conversion"]There are only two ways you can increase your online sales. You can increase the number of visitors to your site through SEO, PPC etc and play a quantity game. Or you can be slightly more efficient with that marketing spend and convert more visitors of whom you already have. If your site is converting 2.6 buyers for every 100 users, would you rather throw more users at it, or convert more browsers to buyers?[/blockquote]

I admit, there are a few tactical persuasion techniques in the above prose to frame the recipient’s way of thinking. That being said, it is true, there are only two ways to increase your sales online; you can acquire traffic or convert it. You can do one or the other but the ultimate aim is to do both.

And thus we come to the debate of SEO v CRO.


In the red corner we have search engine optimisation. A well known, well-utilised and often skeptical practice made as such by the advent of low-level blog posts (don’t get me started). Arguably, it’s a safer option as it’s more known and there is plenty of research to prove that better rankings equals higher traffic. Although there is counter research to suggest that better rankings don’t necessarily mean higher traffic, just better traffic; with more intent. I stray from the point. A legitimate, well versed, well educated and high number of traffic is a requirement for any site and is also a requirement for an effective conversion optimisation structure.

They say what is the point in sending traffic to a site that doesn’t convert? I would say, what is the point in undertaking a rigorous and effective optimisation program when there isn’t enough traffic to make experiments statistically significant within an efficient time frame? The traffic needs to be there before starting an effective conversion optimisation process otherwise we’ll be spending months waiting for tests to become significant. We arbitrarily, from experience, place this figure at about 30,000 uniques per month.


In the blue corner we have conversion rate optimisation. The debatable new kid on the block who proves to be more efficient, more strategic and yet suffers the same fallbacks as it’s more mature sister. Written by a bias 3rd party (me), I have to place my money on conversion optimisation for one reason; efficiency. It is an extremely efficient method of converting existing traffic to your site and proving it’s worth and ROI through data.

[blockquote color="#a5d2d0" bordercolor="#a5d2d0" author="Kate Morris"]SEO is worthless if the conversion isn’t happening[/blockquote] [Source]

When we look at the importance of what ‘conversions’ mean to the business they mean one thing; revenue (well, actually, profit). William Reed mentioned that “SEOs haven’t always taken responsibility for revenue. Their job has always been to increase traffic” which is arguably true. This is in juxtaposition to conversion rate optimisation who are judged on the bottom line. That being said with the increase and advancement of algorithm updates SEO's have had to adapt to provide a more ROI driven service to make sure traffic was, not just increased, but also more relevant. 

Equally, let’s take a look at how many Google Algorithm changes there were in 2014 and 2015. In 2010, Google’s Matt Cutts said that Google made one change per day to their core search algorithm. Between 2013 and 2014 in the space of 12 months, that figure stood at 890 improvements. I don’t think I’m wrong in saying that SEO is a constant battle, as is CRO, but search optimisation is a constant battle against a unpredictable 3rd party conglomeration unlike it’s conversion focused brother.

Getting traffic that converts is absolutely critical to your bottom line and although rather crude to say: SEO gets you visitors where as CRO gets you customers. I stand very much on the conversion optimisation side of the fence, and I have to, because it’s like not supporting my own football team when we play away. But that doesn’t mean I don’t value the concept of SEO. I do believe it’s given a bad name, I admit I don’t fully understand it’s efficiency within the market, but do understand it’s relevance. From my perspective, sitting on this side of the red fence (I’m a Manchester United fan), I don’t believe the grass is greener on the other side; I do however believe it’s necessary.

You’re going to ask me what to invest in now aren’t you? Well here’s where I become slightly more diligent in my answer. It’s impossible for anyone to make a recommendation without understanding the context of your business. The answer should be both so the real question should be in what quantities or proportions. What I can say with some confidence is that the wrong approach is separating the strategies. The two should ideally work in harmony to allow for quicker statistical significance when experimenting and facilitating real growth.

Perhaps as a result this article should be called SEO v CRO – The “Chicken or the Egg” of Ecommerce?


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David Mannheim

David is an experienced conversion optimiser and has worked across a series of core optimisation disciplines including web analytics, user experience and AB & MVT testing.

Conversion Rate Optimisation v Search Engine Optim…

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