When you have produced something original (music, an invention, whatever), to make a fortune by lisencing (NOT selling, see below) the rights to it to a big company that can bring it to the masses. Differs from being a sell out
, as you still own the rights, so the big co. can't force you to go mainstream
to make them even more money.
Originated when the electronica
sold the copywrites to every track on the album "Play", for use in ads, films, and TV.