It's all about money, money, money.
Reality shows are so popular with networks because they are really cheap to produce and provide a good return on the investment. Shows like Lost and Heroes are really expensive because of special effects, location, actors' salaries, etc. They have to cram more commercials in, too. If you time shows nowadays, you'll find that there's actually quite a bit less show than there was even a few years ago.
It' always about the money in Hollywood.
