From Airport magazine (maybe airportnet.org but site was down when I tried to hit it):
Frankly, it's doubtful that Shreveport Regional could get coin-operated sets. According to Midwest International, the nation's sole coin-operated TV vendor, Shreveport's 350,000 enplanements probably aren't enough.
"We generally need 500,000 enplanements" to make it worthwhile, said Richard Sandblom, accountant for the Salt Lake City firm, which has about 500 sets in 40 airports, including New York JFK, New Orleans, Orlando, Tampa, Minneapolis and Oakland, and another 1,000 TVs in bus terminals.
Most of his aviation contracts are with airlines, but a few are with the airports themselves, such as San Antonio, Milwaukee and Salt Lake City. The company offers two styles of chiefly black-and-white TV chairs that come in attached sets of three. Each 15-minute session costs 25 cents, of which the airline or airport receives 25 percent.
Midwest International found that the added expense of offering color TVs simply wasn't worth it "because a color TV will get no more playing time than a black and white."