Single-Active-User MRR Share
The slice of revenue riding on one person — MRR that is a single departure away from churning.
What is it?
This is the share of your MRR that sits in accounts with only one active user. It quantifies a specific fragility: revenue that depends entirely on a single person continuing to log in.
If that one user leaves, changes role or loses interest, the account almost always follows. A high single-user MRR share means a large slice of your revenue is one departure away from churning, no matter how healthy the headline numbers look.
How to calculate?
Sum the MRR of accounts with exactly one active user and divide by total MRR. Forty percent means two-fifths of your revenue rides on individual users. Use the same active-user definition as your other usage metrics.
Treat a falling share as a retention win in its own right: converting single-user accounts to multi-user is one of the highest-leverage things a product or success team can do.