Product & Analytics / Growth
Lx Engagement / Power-User Curve ~ (also "L7 / L28", "L-ness", "days-active distribution")
How many of a period's days each user was active -- a distribution of engagement depth, not a single headline number.
The fork, why two teams get different numbers
"L28" (or L7) is used two incompatible ways.
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: Product-analytics convention (no governing body); consumer-social "power-user curve" / Lx framework cited as convention