Things change quickly. A few short years ago, Netflix was nothing more than a mail order video rental business. Since then, it has been growing rapidly and changing. Believe it or not, Netflix today has more U.S. subscribers than cable TV. That's an amazing accomplishment -- and a major hit to traditional cable television. Netflix and cable TV are two different technologies on opposite sides of the growth wave. Cable TV has grown over several decades, but its growth wave has crested in recent years, and it now is on the decline.