The short answer is no, they're not directly linked. The longer answer is that CRO does indirectly affect SEO.
The goal of SEO is to drive organic traffic to your website by optimizing your site for certain keywords that Google (or other search engines) will consider related to your business and to the interests of the potential reader.
With CRO, the primary focus is to also optimize your website. But unlike SEO, the purpose is very different.
With CRO (Conversion Rate Optimization), the goal is to improve the overall user experience (UX) and flow, so that the visitor will be more likely to perform the desired action. And the goal of CRO is less traffic generation but converting the user once they land on the site.
Although these two forms of optimization are quite different, they do happen to be somewhat interlinked with each other.
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One of the factors that Google considers for ranking your website amongst different keywords is the usability of your website, the bounce rate, how much time people spend on the page, and your site speed.
Naturally, if you are going through a conversion rate optimization process, you'll be making changes to your website which will make it much more engaging, easier to use, and as a result, may influence these engagement metrics.
For example, if you have a jewelry store and people normally land on your home page from Google, but the hero banner has very little information about what you're selling and the emotional benefit of the product, then it's likely people will abandon the page almost immediately.
Again, following CRO best practices, the user needs to be aware of what the website offers and why it's important to them within just 2-3 seconds of landing on the page.
So in the case of this jewelry store, because of the low engagement and high abandonment, Google will consider these factors and likely move this store down the Google rankings.
What's the result?
Fewer impressions on Google's search engine, and fewer clicks.
Despite this, it's impossible to say that CRO is directly linked to SEO.
There are plenty of websites out there that have a terrible website experience, and yet, they rank very highly on Google and other search engines.
This is most likely because Google considers the content to be incredibly valuable to the reader, even if the website arrangement or flow is a bit disturbing.
In other words, they are in many cases correlated to one another. However, it's an indirect correlation.
And even though they're indirectly correlated, a business that is making an effort to improve their SEO should most likely be focusing on CRO as well.
How does SEO and CRO work together?
Any business that is making an effort in generating more traffic (especially when it comes to SEO which has mostly long-term ROI), should also be focusing on CRO. SEO becomes one of the marketing channels or acquisition channels that lead to your website.
And if you don't work on your conversions then you may have a bad site experience (or a "leaky funnel") and get all this traffic but not many conversions.