Arcade games in the 1970s-1980s were placed in locations around the world and used coins for payment. A coin shortage occurred in Japan with the popular game Space Invaders. From the 1980s-2010s, game companies distributed games through proprietary consoles sold in retail stores, which was lucrative as consumers needed the specific console to play games. In the 2010s to present, digital distribution has become the norm, as games can be downloaded without physical disks, saving companies money on manufacturing and distribution. Companies now monitor players online to improve games based on user behavior and feedback.