Nothing bakes a couch potato more than getting emotionally invested in a TV show only to have a bunch of short-sighted network suits pull the plug on it before it really gets rolling.

The days of allowing television series a chance to cultivate viewers over a season or two and be nourished to success through word of mouth are long gone. With competition intense in the ever-expanding TV universe, shows either hit it big immediately or get the ax within a few weeks - too soon even to get into syndicated reruns.

But now series that were quickly canceled are not necessarily gone forever. Just as many box-office failures have been able to find new life in America’s living rooms, so short-lived small-screen classics like Boomtown, Sports Night and Freaks and Geeks are doing bang-up business on DVD.

"It’s numbers and it’s economics," says Dalton Ross, senior writer and DVD critic for Entertainment Weekly magazine. "A show like Freaks and Geeks could only pull in 5 million people to watch. Well, as a network show, that’s a disaster. But if those 5 million people watching are hard-core fans, really invested in the show, and 10 to 20 percent of them would go out and buy a DVD set, then it’s going to be successful on DVD."

That’s why shows that networks couldn’t wait to get rid of during their initial runs are now suddenly being dusted off - and in some cases even put back into production or prepped for the big screen.

Shows like Firefly, a sci-fi series from Joss Whedon, the creator of Buffy the Vampire Slayer. The gritty, well-acted Firefly, in which an unlikely band of ne’er-do-wells share various interstellar adventures, was such a surprising success on DVD (boosted by three episodes that were never broadcast) that Whedon decided to make his feature-film directing debut a big-screen spinoff from the series. The upcoming Serenity, named for the spaceship on the show, reunites the original cast.

Though a feature-film spinoff is unlikely, The Family Guy is another failed series that has become an unprecedented post-cancellation success. Fox’s animated Simpsons-like series went off the air after three seasons, only to go back into production after a very successful DVD release.

Could there be a similar comeback in the cards for this fall’s crop of DVDs from failed shows?

The Harsh Realm, from X-Files creator Chris Carter, might be a good bet. Though The X-Files was Fox’s franchise series throughout the ’90s, Harsh Realm (arriving today on DVD) was killed after only three episodes in 1999. (Its remaining six shows eventually aired on sister net FX.)

Even in a TV environment that demands instant results, the abrupt departure of Realm, Carter’s ambitious, complicated series about a pair of soldiers sent into a virtual world to bring down a rogue general, seemed a bit, well, harsh. Carter believes it’s because the show was ahead of its time.

Another contender for a second life is the 1999 WB teen comedy Popular (season one arrives Sept. 21), the story of a pair of high-school enemies reluctantly thrust together when they become stepsisters. The six-disc set has precious few extras, but it includes audio commentary and footage that was never broadcast.

Many of the shows coming to DVD, such as Stephen King Presents Kingdom Hospital (Oct. 12) and the amusingly weird, puppet-powered, showbiz satire Greg the Bunny (Oct. 19), never lasted long enough to make it into reruns, much less syndication.

Then there are series such as Fox’s Keen Eddie (Sept. 7) - about a disgraced New York cop sent to work with Scotland Yard - that managed to build DVD anticipation after being picked up by a smaller network, Bravo. The DVD set includes six episodes never aired on Fox. The strategy has worked for shows like My So-Called Life (from ABC to MTV) and Freaks and Geeks (from NBC to ABC Family).