Being concise and to the point - a powerful way to communicate and keep your audience's attention. This is Seth Godin's point in his blog today.
How good are you at accomplishing this? I know I'm usually not very good at it. But I won't belabor the point, because that will defeat the purpose.
Bottom line - Know that you only have someone's attention for so long. If you can't make your point right away, you will not only increase the likelihood of them getting what you want them to get, but you will also likely have them wanting more.