Discrimination based not on race, gender, or religion, but rather on a disturbingly horrible iTunes music library discovered through a school or job network.
Refers to the "shared music" feature available on iTunes in which one can browse the various music libraries of the co-workers or classmates in the network. Often requires awkward explanation of why you have "that song."
Mike accused me of playlistism when I questioned his collection of Color Me Badd b-sides.
Discrimination based on the music on someone's computer playlist. Of course, if someone's taste is bad enough to include Daniel O'Donnell on their computer, they probably deserve it.