Possibly a large one.
That's a conclusion raised in Games that make leaders: top researchers on the rise of play in business and education, from the Wisconsin Technology Network.
A friend was talking about how the Army had distributed a game, for free, that seemed to be catching on with a lot of young users. So, this quote from the article wasn't that much of a surprise:
One of the biggest users of games as training tools is the U.S. Army, which released the free tactical game America's Army to boost its recruitment and has worked with commercial game companies on a variety of other titles.
One of the words I've been seeing lately in education and usability is "engageability." It is easier to teach someone when they are interested and actively engaged.
Seems that classrooms may have something to learn from a gaming industry that earns ore in sales these days than box office sales from Hollywood.