Ubisoft CEO Yves Guillemot told GamesIndustry International that the $15 DLC Far Cry III: Blood Dragon sold over 500,000 copies in only two months.
Companies usually do not release details about downloadable content sales but showing sales to be so high can't hurt. As anyone who's played Blood Dragon knows, the crazy stylistic departure from the Far Cry series does for your eyes what a Major Lazer song does for your ears. It's a refreshing neon escape from realistically-colored and over-serious shooters, taking a not from Duke Nukem and Serious Sam.
If you haven't played Blood Dragon check out the trailer and do yourself a favor and get this day-glow, cyborg stomping, laser-bash.