If you feel fees must be charged, could a "sliding" scale be used

Could a sliding scale be used to charge those that use Intellectual property.  For example, if someone sells a million dollars worth of software, he or she is charged a heavier fee, as opposed to someone who makes a thousand dollars.  On the other hand, if someone implements shareware that is not sold (or any derivation of the product -- products derived from the shareware that use the patented IP should be charged just as those that use the IP from scratch) then no fees should be charged.
thx
steve