What big companies need to do to avoid the wrath of the
BSA. They have people whose entire job it is to make sure the company has an appropriate license for each piece of
payware it runs.
There is also license management software: You have a license server which the software contacts to obtain permission to run. This has the benefit that it makes it possible to get by with fewer licenses: in some licensing schemes, you need only one license per copy of the software that is actually running at the same time, not one for each computer it is installed on.