Heat maps are a way of measuring user behaviour on your site. You can cover a few different metrics through heat maps, such as Hover (Mouse/Eye) maps, Click maps, and Scroll maps. Each of these maps measure different things and as such they can be used to make different inferences about the behaviour of visitors on your site.
Hover maps, otherwise known as mouse or eye tracking, gives you an idea of where the mouse of the user spends the most time on your site. This is supposed to show you where most of the user’s attention was, hence why it is also called eye tracking. Each heat map has its merit, however with hover maps you need to be careful not to place too much emphasis on where the mouse is as there are studies which show that where the mouse is doesn’t necessarily correlate to where the user’s attention is focussed. The Hover map can be used to detect if there are any items on your page that are distracting away from your key USPs. For example, if you see the majority of the hovering on your site is over an animation rather than your key page content it may help conversions to remove this animation. This would allow users to spend that time focussing on your products or services.
Click maps measure exactly what you would expect them to measure, where the most clicks occurred on your site. This is a much more trustworthy metric as you are measuring something definable, rather than something more fluid like user attention. Therefore, this allows you to measure what draws in the most users to search further into your site. This can be helpful in how you lay out your header as you want the items getting the most clicks to be the most prominent. It can also help you see if there are things on your page getting clicks that aren’t links. This is easily resolved though as you should either make it a link or make sure the offending item doesn’t look like a link.
Scroll maps measure how far down a user scrolls on your page. This doesn’t necessarily show attention or interest but it shows the percentage of all the users on the page that scrolled to a certain point before leaving. This allows you to see the content that users view before leaving the page. It also allows you to see how many users leave the page before scrolling below the fold. Scroll maps allows you to judge where you should put much of your most important content. Obviously, the important items of your website should be kept above the fold, and for links should be included in your header. However, it also allows you to judge how to lay out the rest of your page as well. It can also work in conjunction with Click maps, for example if you run a Scroll map and a Click map on a product page and you are seeing an item getting lots of clicks but it is below the fold it may help to include this product above the fold to get even more conversions. Whilst heat maps are a useful tool they are just one aspect of how to convert users on your website. In order to fully optimise your website to convert users or keep their attention your also need to keep in mind UX, SEO, and overall design. However, they can be very interesting and give you an insight as to how users spend their time on your site.