(or more specifically, patent your invention and wait until someone else wants to use it. If this seems unethical, remember you will usually be blocking big evil corporations, not other inventors, and that the big evil corporations would always do the same thing to you if they could.)
Sell patents.
(or more specifically, patent your invention and wait until someone else wants to use it. If this seems unethical, remember you will usually be blocking big evil corporations, not other inventors, and that the big evil corporations would always do the same thing to you if they could.)