White Label Pricing (20% discount) is granted to customers that deposit $1000 or more in our system.
In my experience, what I've seen is that you should clarify right from the beginning that they should use it within a year (365 days).
Also, you should work on to your strategy to bring clients back to the platform. What you want is to people to spend that money as soon as possible so they would spend more and more.
Remember, a great e-commerce platform gets 50% of their revenue from returning customers.