Escalator Pitch

The more common term is "elevator pitch."

The premise is you have some great idea (like a plot for a screenplay) and you find yourself on an elevator with someone who can turn the idea into reality (like Steven Spielberg). The elevator pitch is the short, pithy sell-job for the idea. Lots of would-be entrepreneurs are at home right now practicing their elevator pitches in case they ever bump into Elon Musk.

Usually, "escalator pitch" is just used as a synonym for "elevator pitch." Other times, people (these are usually bloggers in the business self-help realm) make some sort of clever distinction between them. In these situations, the typical hook is that the escalator pitch is shorter, presumably under the premise that you're passing the person going the opposite way on a different escalator. (Whether an escalator ride is actually shorter than an elevator ride seems highly dependant on the situation. Ever ride the escalator at the Silver Spring stop in the DC-area metro? Epic.)