I'm new to DNN.  I'm looking for a good .net application framework to get me started on a specific line of business application.  I'm not sure if DNN fits the bill.

My application has these requirements:

1.  The app could have thousands of clients.  Ideally, they would be able to reach the application with their own client specific url (e.g. sears.myapp.com; or ibm.myapp.com; etc...)  Adding a new client should be dynamic.

2.  Each client would have their data and users separate from other clients (e.g. an administrative user for that sears would only be able to add/edit/delete users for sears; same goes with data.)  Even DNN core modules like documents, calendar, etc.. should be client specific.

3.  Each client may want their own custom skins or branding for their app.

Is this something DNN can handle or should I be looking for something else?  If so, how is this best accomplished in DNN?

Any help would be greatly appreciated.