The term, elevator pitch, is most associated with venture capitalism, that volatile field of commerce where ideas meet money. An elevator pitch involving Thomas Edison and a nineteenth-century financier might have gone something like this:

"My lightbulb harnesses the exciting new technology of the electric current. It's safe, it's reliable, it's easy to use. It delivers much better light. Consumers love it. Businesses operate far more efficiently. It's the wave of the future."

Fifteen seconds exactly.

"The wave of the future" might have scared off a more conservative potential investor. Thus, Edison would have altered his pitch slightly by pointing out that electricity is an old and proven technology - dating back to the telegraph - rather than a new and exciting one. Either way, he's telling the truth, but he's reframing it in a way to suit his particular audience. In effect, he is telling them what they want to hear.

Our whole conversational life is a constant succession of elevator pitches. People have notoriously short attention spans. They are impatient. They get distracted easily. You may have all the time in the world to listen, but you have a mere 15 seconds to make an impression. Sixteen seconds or more, and you are living on borrowed time. There is a phone about to go off, a baby ready to throw up, a tree on the brink of crashing through the ceiling. Seventeen seconds and you are virtually certain to be looking into a pair of glazed eyes.

Less is more. The Old Testament advises, "let your words be few." The New Testament warns that you will be held accountable for every word you have spoken. No doubt, on reflection, you would like to take most of those words back. Keep that thought in your head the next time you are thinking of opening your mouth.