Definition
Engagement rate is the share of people who interacted out of everyone who could have. It's defined differently in different places:
| Where | Common definition |
|---|---|
| Product | Active users ÷ all users, in a period |
| Website | Engaged sessions ÷ all sessions |
| Social media | Interactions ÷ impressions or followers |
| Clicks ÷ delivered |
Make the definition explicit
Because the term means so many things, write down exactly what counts as engagement before tracking it, and don't compare rates defined differently.
Engagement that means something
On a website, a scroll, click or key press is a better sign of a real person than a page load: bots load pages but rarely interact. LogZuno counts a visitor as a person only after real input; see web analytics.