German broadcaster ProSiebenSat.1 has bought a 20 percent stake in U.S. online video maker Collective Digital Studios (CDS) to win more viewers in the global video market. CDS produces, distributes, and markets videos via websites such as Googles YouTube and generates almost a billion video views per month with 600 channels and more than 100 million subscribers, ProSieben said in a statement on Thursday. Its formats include The Annoying Orange, Epic Meal Time and FreddieWong/Video Game High School. ProSieben, whose own Studio71 has more than 100 million video views per month, did not disclose how much it was paying for the stake in CDS. With consumers increasingly using smartphones and tablet computers to watch videos and listen to music, broadcasters such as ProSieben and its rival RTL Group are expanding their online media offerings to win viewers.