I get in class new student teachers who need an endorsement that they have taken a programming class. Sometimes these students aren't that interested in programming, they don't see how it will apply to them.
My lesson: "If you learn to program, and put your lessons out on the web you will reach more students than you ever would in the classroom." And I practice what I preach. I've been working with my on-line book ProgramArcadeGames.com a lot this summer. Traffic has increased, thanks mostly to reddit.com. Here is a graph of unique visitors per day:
Even more important, according to Google Analytics, about half of the visits are returning visitors. During the month of June I've had over 1,300 visits where more than ten minutes was spent browsing the site. About 500 of those spent more than twenty minutes on the site.
I am reaching more students on-line than I am in the classroom.