Analyze5 min read
Engagement: stickiness and scroll depth
Visitors and pageviews count arrivals. Engagement counts involvement: how often the same people come back within the range, and how far they actually scroll once they're there.
Stickiness
For every visitor active in the range, Mrkr counts the number of distinct calendar days they were active, then buckets visitors by that count. A range of 30 days can bucket someone anywhere from 1 active day up to 30.
Returning share- The share of all visitors active on more than one day in the range.
Avg. active days- The mean number of distinct active days per visitor.
This answers a different question than a retention chart. Retention asks whether someone came back at all; stickiness asks how often. A site where almost everyone shows up on exactly one day is a very different business from one where a quarter of visitors return on five separate days, even if their total visitor counts are identical.
Scroll depth
For each page, Mrkr shows what share of pageviews reached the 25%, 50%, 75%, and 100% scroll thresholds, plus an average depth.
The denominator is pageviews that reported a scroll threshold at all, not every pageview of that page. The tracker deliberately stays silent on pages with under 240px of content below the fold, because a page that fits entirely in the viewport was fully seen without any scrolling, and reporting "100% scrolled" for it would describe something the visitor never did. A short page legitimately shows no scroll-depth row at all, and that's a meaningful answer, not missing data: it does not mean 0% of visitors scrolled.
Where it fits
Scroll and engagement pings are auto-captured by the tracker: see Scroll and engagement tracking for what triggers them on the client. Filters and cohorts apply to both stickiness and scroll depth the same way they apply everywhere else; see Filters and segments.