SyFy is running mini-marathons leading up to Halloween. These are, as you might expect, all supernaturally themed. They kicked it off with "Brimstone" which I saw, loved, and mourned when it first aired and then unceremoniously had the plug pulled early on. The other day they ran a show I'd not heard of (in part because I'd been overseas when it aired), "Haunted," that I enjoyed enough to park my butt in front of the television most of that. (My laptop came downstairs with me, so I didn't completely waste the day.) Like so many other shows, it died quickly, most likely due to ratings and other factors, and like so many other shows, I found myself lamenting it's short run.
This is one of the problems with television as a medium to tell stories in. With books, where once an author has been published, it's a good bet they'll be published again, and so if they have a continuing character you can be guaranteed further exploits. Spenser has been going for nigh on thirty years at this point, and I expect will continue to do so until Robert Parker finally puts down his pen for good. With some ongoing characters that means more growth than others, but is also means there's either a sufficient back catalog to keep you busy, or the promise of future works to happily devour.
In television, however, once the plug is pulled, that's it. (Unless it's a Joss Whedon show, whereby cancellation just leads to a change of media. Though I could use more "Firefly" and less Buffyverse from his comic empire.) The story is done, the actors move on, and whatever interest you had in the story has to make do with either reruns on cable or buying the DVD packages. When they exist. (Which a "Brimstone" collection does not. A serious oversight in my opinion.) You're left with fan-fiction, which is sketchy at best and weird and badly written at worst (recently lampooned to excellent effect in "Supernatural" - which I recommend to horror fans), or crafting your own "what if's" in your head.
If the story ends on a cliffhanger or something like that it can be even more frustrating. I remember a very short-lived series called "The Fifth Corner" that was a spin on the concept behind the "Bourne Identity." It was one of those shows where, for every answer you get, more questions popped up. I liked it, it was well done, and it got far enough where you could tell it was only going to get better ... and then some international something or other happened, I don't remember what, and it got pre-empted for news coverage, and once the something or other was over, the show was gone.
Watching "Haunted" also got me thinking in reverse about some book series. There are a couple I have read where, for whatever reason, as a reader you start to wish the last few books in the series hadn't been written. Books that would have "jumped the shark" had they been television shows. You read them anyways, unless they get really bad, just like you watch them anyway (last season of the "X-files" comes to mind), but you know that pretty much every time you go to read a new installment, it's going to be a disappointment. If the author keeps going, you may even just abandon them entirely. It's enough to make you wish that some series and/or authors were dependent on ratings, and that once they fell below a certain readership they'd be asked to pull the plug on it.
With books, though, unlike in television, once you've managed to get your pilot show aired you're pretty much guaranteed to keep going for as long as you can churn them out. There's always another publisher out there willing to take an author with a proven track record on, even if there last few outings don't get the critical acclaim of the initial forays. (As in television when another network picks it up, that doesn't always mean you get the same quality of stories. If anyone remembers "Sliders" - the version on cable wasn't the one on Fox by any means.)
I suppose it's like that Billy Joel song - "Only the Good Die Young." Only without the whole "rock groupie Catholic girl sex" thing going on.
In the meantime, there's cable television reruns and DVD rentals. And knowledge of the inevitable - that other shows, other stories, will come along, only to be gone just when they were starting to get really interesting.