Comcast XFINITY TV → Re: [HD] FIOS Moving to MPEG-4 HD

That's how some series shows I used to watch ended. One of them kept going on top every season but at the same time, most of the cast wanted to pursue other things and couldn't do a lot outside of the series due to it's work load.

Another fine example of that is the show Home Improvement. Tim Allen was offered $50 million per episode by the ABC network to keep the show going rather than ending it due to it's popularity. After talking it over with other cast members he still decided to end it so him and other cast members could go on to other projects or in some cases, some cast members decided to retire after a good long run like that.

EDIT:
Also keep in mind that some die out due to greed as well. Some shows will start out on their way to the top or make it to the top quickly. Some times actors/actresses get to big for their britches and will demand more money than what can be afforded with no bending or compromise in sight. In a lot of those cases you just can't swap out one person for another to play that role after some one has well established themselves in that role. So the only logical choice there is to just end it.

Cool. Speaking of Home Improvement, it's interesting that only Tim Allen, Patricia Richardson, Richard Karn, Pamela Anderson, Blake Clark, and Zachery Ty Bryan continued acting where as Jonathan Taylor Thomas continued until 2006, Taran Noah Smith continued until 2002 and Earl Hindman continued until 2003 upon his passing.