In years 2000/2001, as the dot-com implosion was happening, I worked for a company where we did patent disclosures (I spent a long time talking to a patent lawyer) discussing in depth ideas for billing systems, including a vendor / distributor / consumer model (where any entity could be any one or a combination of those w.r.t. a product), data structures, data-collection frameworks, billing "metrics", passthrough-billing-with-a-cut, differential pricing, resale of combined products, etc. These were turned into patent applications that perhaps merited becoming full-blown patents, or perhaps not. Given the recent rash of companies doing this (e.g., https://www.monetize360.com/), I think they were patentable ideas 20+ years ago. The referenced applications should give some prior art coverage for many patent issues one might run into.

Of course, the vendor/distributor/consumer model can become vendor-many-clients through simplication, same ideas hold.

As it turned out, the company was lucky to have some data-storage-discovery-and-inventory software built as part of the bigger eventual vision that attracted a buyer. It was not the time to work on ambitious greenfield stuff, I guess. The patents were not relevant to the acquirer, and they lapsed at some point.

https://patents.google.com/patent/US20030083998

https://patents.google.com/patent/US20030084000

https://patents.google.com/patent/US20030083892

https://patents.google.com/patent/US20030083995

https://patents.google.com/patent/US20030083994

https://patents.google.com/patent/US20030084145

https://patents.google.com/patent/US20030083999

https://patents.google.com/patent/US20030084060

https://patents.google.com/patent/US20030084343

https://patents.google.com/patent/US20030084341

[edit: 2000 -> 2000/2001 ... "any patent issues" --> "many patent issues" ... a few other in the inventory of ideas ... simplification of model to vendor-many-clients ... fixed one link]