My wife and I used to love Lost.  The First two seasons were great we were sucked in from the openning shot of the Pilot.  However latemid second season the signs of trouble and annoyance reared up. 

1.  So many plot lines that seemed to strech on forever with no conclusion even remotely insight.
Things left out in the cold forever it seems, the whole Micheal/Walt thing was really annoying, and then to have a 20 second reuniuon and then have them sail off....UGH!  What did the others want with Walt?  What happened to him on the otherside of the Island, its all still a mystery...we wanted some conclusion to that, we never got one.

LOCKE! Why was he in the Goddamned Wheelchair...I wanna know, I wanna know now, stop stringing us along. 'nuff said.

What is the Dharma project, how is it related to the others?  What are the others up to, why are they professing to be the "Good Guys" and killing people, what the Hell was Ethan's problem?

Whats the Deal with Danielle?  What happened to her family, where is she now, how does her stolen baby related to the others? 

Whats the deal with Claire's Baby why were the others interested in him?

What the hell did the others want with Sawyer and Kate?  We at least have some clue about Jack now, but what about them just bait to get Jack to do what they wanted?

Why did we have all that stuff about the other end of plan just to kill everyone except Bernard?

I could go on...but its just driving me nuts thinking about it.

2.  Re-Runs, Re-Runs, Re-Runs...thats a great way to loose Viewer interest and kill shows.  Very iritating.

3. Commercials, Commercials, Commercials, they got out of control in the late Mide Season two and came to a head at the end of season, it hasn't gotten any better in Season 3.
4. Screwing about with Schedule and time slot.  9 was the right time 10 is too late, its not a 100 O'clock show, its really not...and starting late in the season, showing 6 episodes and then disappearing for over 2 months....Not good, not a way to get an keep viewer loyalty.

Does anyone else remember when shows started in September, ran pretty much all of their episodes back to back until the end of the run, maybe thorwing in a re-run, or not showing only during holiday weeks.  Of couse the length of a season was somewhere between 22-26+ insome cases episodes, Commericials where pretty much on the 0, 15, 30, 45 and lasted a couple minutes at most as well.

You want to know why TV viewership is falling off, why viewer loyalty is so hard to win and keep...look no further than Lost as a case study.  Its done everything possible to piss off its viewer base, and then some.