Otherwise it was on service provider to collect whatever software the customer is using and charge for it. And if you don't, prepare for a hefty fine. Windows of course provides SIL infrastructure to do just that, but all that implies server has to be configured in some way.
And then the price for the licence ofcourse...
I really like Windows Server OS, but the effort it puts on part of service provider - no wonders everyone wants and offers to deploy Linux.