A few years ago, publishing companies started to sell digital copies of their magazines. This study investigates a consequence of this change: the increasing online trade with illegal copies. We collected data on almost 10,000 issues of German magazines that are illegally offered online. The files are distributed in a three-sided market, in which a small number of platforms bring suppliers of illegal copies, consumers, and advertisers together. The market has been growing rapidly—between 2009 and 2012 by a factor of 10. In contrast to the legal magazine market, the illegal trade mostly concerns IT and consumer electronics magazines.