Where can I find scroll depth on Google Analytics?
The scroll depth threshold is a built-in variable on Google Analytics, which means it's usually enabled by default. However, you can double-check this variable is switched on by visiting the “Variables” section in your Google Analytics toolbar. Click "configure" and scroll until you see “scrolling”.
What is scroll tracking?
Like the name implies, scroll depth tracking is a method of tracking how users scroll throughout your site. Scroll tracking can be applicable to almost every site, and provides insight into the non-interaction behavior of users on your site.