Average Revenue per Paying Customer is the average amount of revenue that each of your paying customers generates.
This metric is calculated by dividing the total revenue generated by your customers in a set time period by the number of paying customers you had at the beginning of that time period.
For example, if you have 100 customers and they generate $1,000,000 in revenue in a quarter, your ARPC is $10,000.
This is a very important metric to track because it gives you a good idea of how much revenue you can expect to generate from your existing customers in the future.
If you have a high ARPC, you're in good shape. If your ARPC is low, you need to find ways to increase it.