kpapke

I think he means don't be afraid to work at a problem you care about and you'll probably end up helping someone else. Although I'm not sure if he's saying the opportunity to provide value for others is the goal or just a byproduct of your own interests...

I haven't seen anybody raise the point about the cost of living. The salaries are more because the cost of living is higher. With 50k you can afford a mortgage for a nice house in the midwest, but in NYC the equivalent monthly income will qualify you for a tiny studio or 1 BR apt.