Ah well, time to bit the bullet, I think. I've been looking around for ideas on how to measure audience engagement and I've found this post by Ronald Patiro.
Lots of great ideas such as:
- Visitor Engagement Index = (Visits) / (Visitors)
- Take Rate = (# of Visits Taking Part in Desired Activity) / (Visits)
- Repeat Visitor Share = (Repeat Visitors) / (Visitors)
- Heavy User Share = (# of Visits with X or More Pages Viewed) / (Visits)
- Committed Visitor Share = (# of Visits Lasting Longer Than X Minutes) / (Visits)
- Committed Visitor Index = (# of Page Views in Visits Lasting Longer Than X Minutes) / (# of Visits Lasting Longer Than X Minutes)
- Committed Visitor Volume = (# of Page Views in Visits Lasting Longer Than X Minutes) / (Page Views)
- Bounce Rate = (# of One Page Visits) / (Visits)
- Scanning Visitor Share = (# of One Minute Visits) / (Visits)
- Scanning Visitor Index = (# of Page Views in One Minute Visits) / (# of One Minute Visits)
- Scanning Visitor Volume = (# of Page Views in One Minute Visits) / (Page Views)
- Average Order Amount = (Total Sales) / (Total Orders)
- Sales Per Visit = (Total Sales) /(Visits)
- Repeat Order Rate = (# of Orders From Existing Customers) / (Total Orders)
- Order Acquisition Ratio = (Marketing Expense/Number of Orders) / (Marketing Expense/Visits)
- Conversion Rate = (Number of Sales) / (Visitors)
- Page Views per Visitor = (# of Page Views) / (Visitors)
- Average Time on Site
