Scroll Depth is a small Google Analytics plugin that lets you measure how far users are scrolling on a page. It monitors the 25%, 50%, 75%, and 100% scroll points, sending a Google Analytics event for each one.
Why’s it important?
Page Scroll Depth can be a good indicator for engagement: the further visitors scroll down a page the more content they wanted/ will have consumed and engaged with. Also knowing how far people scroll can help you determine what to do with the page and the content.