By 1972, Baer’s idea had become a product, the Magnavox Odyssey, a primitive home video console; it had no sound and ran on C batteries. Most of its graphics, such as they were, were produced by affixing a plastic decal to the television screen connected to it; players controlled a spot of light, and used it to bat around other lighted spots in stylized versions of tennis or hockey. Baer ultimately sold about 350,000 units.

Tim Wu, The Attention Merchants, loc. 673