I think you could get away with offering a one time payment if you restrict the time you’d supporting your software with updates.
So for example you have X Program that has a one time license which costs $100, you promise to keep updating X Program for let’s say 3 years… after that time passes, those people could keep using your program but they wouldn’t receive any updates without paying some sort of upgrade fee or you could choose not offer one at all if you’re looking for a clean exit.
So for example you have X Program that has a one time license which costs $100, you promise to keep updating X Program for let’s say 3 years… after that time passes, those people could keep using your program but they wouldn’t receive any updates without paying some sort of upgrade fee or you could choose not offer one at all if you’re looking for a clean exit.