I'm in need of an already existent content distribution system (so we dont' have to spend extra cash to build from scratch).
Not the usual one where you have a list of emails and it sends the same information out to everyone. I'm looking for something that could handle many clients, who all have their own users that they want to distribute content to. Not only this, but I would like each client to be able to distribute different content to the different users, if need be.
Example:
Let's say there are 2 customers using this solution:
1. Personal trainer
I want it so he can send different training regimens to different clients of his through our system. Or if it's a multi-stage training regimen, if he would have many clients of his using the same regimen, to be able to send different stages to different clients, depending on what week/level they are at.
2. Online professor
Same premise - to be able to send different stages to different students, depending on what level they are at, but not all are at the same level at the same time.
I know there are many software guys on here. If you need more info or would like me to clarify something, please just ask.



