I was visiting with family over the weekend, celebrating an uncle's birthday and meeting with cousins I rarely get to see. Nobody in my extended family is much of a gamer anymore. And the ones who stopped gaming are outnumbered by those who never gamed. Of course, whenever I happen to have a game at hand that I think has even a small chance of attracting one of these luddites, I jump at the chance.
To sell people on a product when they're only looking at it to be polite, the presentation must be captivating in the first five minutes.
Unfortunately, that's rarely possible as games are today. Odds are, the place you left the game saved or the gameplay with which you must begin the presentation is not the most captivating scene. You need at least 10 minutes just to get to the scene that will make your friend or family drool.
So it's a small thing to keep in mind when designing a game. The easiest way is to include a trailer for the game with the game. So when you want to show the game off to someone -- so they'll play with you, go buy the game, or just understand how anyone could be interested in video games -- you can show the person quickly before that small window of opportunity closes.