Billions of transistor radios are estimated to have been sold worldwide between the 1950s and 2012. Prior to the Regency TR-1, transistors were difficult to produce. Only one in five transistors that were produced worked as expected (only a 20% yield) and as a result the price remained extremely high. When it was released in 1954, the Regency TR-1 cost $49.95 (equivalent to $ today) and sold about 150,000 units. Raytheon and Zenith Electronics transistor radios soon followed and were priced even higher. In 1955, Raytheon's 8-TR-1 was priced at $80 (equivalent to $ today). By November 1956 a transistor radio small enough to wear on the wrist and a claimed battery life of 100 hours cost $29.95. Sony's TR-63, released in December 1957, cost $39.95 (equivalent to $ today). Following the success of the TR-63 Sony continued to make their transistor radios smaller. Because of the extremely low labor costs in Japan, Japanese transistor radios began selling for as low as $25. By 1962, the TR-63 cost as low as $15 (equivalent to $ today), which led to American manufacturers dropping prices of transistor radios down to $15 as well. Transistor radios were extremely successful because of three social forces — a large number of young people due to the post–World War II baby boom, a public with disposable income amidst a period of prosperity, and the growing popularity of rock 'n' roll music. The influence of the transistor radio during this period is shown by its appearance in popular films, songs, and books of the time, such as the movie "Lolita". In the late 1950s, transistor radios took on more elaborate designs as a result of heated competition. Eventually, transistor radios doubled as novelty items. The small components of transistor radios that became smaller over time were used to make anything from "Jimmy Carter Peanut-shaped" radios to "Gun-shaped" radios to "Mork from Ork Eggship-shaped" radios. Corporations used transistor radios to advertise their business. "Charlie the Tuna-shaped" radios could be purchased from Star-Kist for an insignificant amount of money giving their company visibility amongst the public. These novelty radios are now bought and sold as collectors' items amongst modern-day collectors. Since 1980, the popularity of portable radios has declined with the rise of portable audio players and smartphones, which allow users to carry and listen to the music of their choosing and may also include a radio tuner.