Why Are the Previews Shown before a Film Called "Trailers"?

Today, we show up at the cinema to see a film scheduled to begin at a specific time. You get your popcorn and soft drink, and settle in. First come a few commercials, and then some “coming attractions” -- high-energy promotions of movies scheduled to be released in the future. These short reels are called trailers, even though they’re shown before the feature film. They got that misleading name decades ago when they were shown following the main event, beginning in 1913 at Loew’s movie theaters in New York City.

Spending the day at the movies:

• In the early days of cinema, theaters showed an endless loop of double features, cartoons, newsreels, short films and trailers. Patrons would come and go, often in the middle of a movie.
• By the 1930s, studios realized that trailers had excellent promotional value, and played them right before the main feature. Trailers are now commonly watched online, as well.
• Loew’s very first trailer was a brief promotional film for a Broadway play called The Pleasure Seekers. The short featured rehearsal footage from the stage production.