Think of the one time payment as being your royalties paid in advance, in cash, with no need to verify every product sale with every infringer over the next several years....
What type of costs are associated with the verification process? And what about dwindling royalty payments over time as product sales drop in the face of new product innovations and/or technology advancements?
Nothing wrong with cashing million dollar checks and moving on to the next infringer....CLEAN and EFFICIENT (times) 200.
