Once you've chosen your money metric, it's time to monitor it in a few important ways.

The first is retention - this is very easy if you are using Mixpanel or any modern web analytics software. You want to make sure that your retention by this metric is improving with each cohort.
Overall active users is also important: monitor the number of unique users who received value per day ("Daily Active Users"), week (WAU), and month (MAU).

Take a look also at average number of times per user that this value is

These are the key measurements that tell you your true user growth.

Here is the retention chart for Ecquire, showing weekly usage of our money metric, the CRM button, because that correlates with value of our product. Each column is another week gone by, and each row is a new cohort that signed up in subsequent weeks.