They are 2 different things. One is selling a service,
the other is selling a digital item.
In both cases, however, there is an agreement between
buyer and seller, and no one is forcing anyone to
do anything.
I returned two $200 laser printers to the store after they tried to impose conditions after sale.
The first was a Lexmark. They had printed a "
patent license" on the box claiming that I did not own the print-cartridge and had to return it to the manufacturer after a single use.
The second was a relatively entry-level HP multifunction printer. It is was "dumb" printer that does not work without proprietary drivers. The EULA said
I was not allowed to install the software on more than one machine: for a network printer.
Stop and ask yourself why anybody would agree to such terms?
I also find your use of the word "digital" troubling. If it can be easily copied (per definition: that is the purpose of digitization), you want to be able to charge for every copy? I suppose copying VHS tapes and old audio cassettes are fine simply because the information is analog.