nickelodeon, Early motion-picture theater, so named because admission typically cost a nickel. Nickelodeons offered continuous showings of one- and two-reel films, lasting from 15 minutes to one hour and accompanied by a piano. The success of the Pittsburgh nickelodeon established in 1905 by Harry Davis made it the model for their rapid proliferation throughout the U.S. By 1910 they numbered 10,000, fueling a huge demand for silent films and projection equipment and providing the impetus for the development of the modern motion-picture industry.