So lets say I create a website for a Medical Association.

If we could have a marketplace in that website, where their service providers can be "posted/promoted" and ranked by the Medical association affiliates. It can become the place to go and look for a service provider (accounts, digital marketing, medical supliers, etc). If it can have an internal review system it will become a really trustworthy place to go to since other "industry" folks already have used those service providers.