ARPPU

Average Revenue Per Paying User

ARPPU is a measurement used to determine the average of how much revenue is generated by paying users over a specific time period.

The formula for ARPPU is: 

Total revenue generated in time period X / Total number of paying users in time period X

Example:

$100 revenue in a 30 day period / 100 users in the same 30 day period
 = an ARPPU of $1.

Note that looking at ARPPU as a daily value vs. a monthly value gives different results. This is because monthly ARPPU for a single user who makes multiple purchases throughout a month might not be included in the ARPPU for a single day.