A corporate purchase entitles the company to make the course materials
internally available for up to the specified number of its employees.
It does not permit use by customers or
in training classes that include non-employees.
If you want to make the class videos available on a central
internally-accessible-only server for your employees to watch,
you must buy a license for at least 1000 employees.
Note that when putting up videos on a company server,
you need to buy a license that covers the number of employees 
that have access to the videos even if not all of them choose
to watch them.
Thus if your company has 2000 employees that have access to
the videos then you need to buy the license that
allows for up to 5000 employees.