Actually clients acquired from running a business are typically called "customer lists" or "customer relationships," and there are recognized methodologies and standards for proving them and establishing values for them. Just my two cents.
What happens, I wonder, if clients are acquired by a person and customer lists / relationships are based on studying / working with that person, and that person dies ? What happens if those students go their separate ways ? Does the orginazation that remains have a claim to those students ? If that relationship was the sole basis for those students being a part of the orginazation ? Or can the go their separate ways ?