Question: I never saw Quantum Leap that much when it was first on, but have seen reruns and like it. How long was it on originally? Thank you. — Joe O., Hermiston, Ore.

Televisionary: Physicist Sam Beckett (Enterprise's Scott Bakula) started his in-and-out-of-body experiences on NBC in March 1989 and jumped around time with holographic pal Al "The Observer" Calavicci (Dean Stockwell) until mid-August 1993. And the only reason the oft-praised but ratings-challenged cult favorite lasted that long was because of fan fervor and another, more important, factor — demographics.

For the 1991-92 season, for example, QL ranked 63rd out of 132 series on the air but stayed on NBC's schedule while the network showed higher-rated shows like In the Heat of the Night, Golden Girls and Matlock the door. Why? The same phenomenon I've blasted in this column before: Madison Avenue's ad buyers want young eyeballs because ad execs are convinced older folks can't be swayed with commercials. So though they were more popular, those three shows were retired because their most visible stars sported way too high a white-hair quotient for the suits to keep them on. (Hey, it's a silly — and unproven — theory to me, but the WB stays in business and shows like Buffy the Vampire Slayer stay on the air because of it.)

QL pulled in more audience members in the crucial 18-49 age group than any other NBC show on the schedule at the time, including the blockbuster Cheers, and was the fourth-rated network drama in that age group. Nearly as important, that season it was up 34 percent among women and 35 percent among men in that bracket, a strong pull for those who decide what commercial time to buy, and so commanded a 30-second ad rate that went as much as $20,000 higher than average. "This is quite a premium for such a low-rated show," a senior ad exec told TV Guide in 1992.

It's interesting that even though it was a sci-fi drama, the show built and kept a furiously loyal audience with its humanity. Leaping into such varied characters as a paraplegic, a killer, a rape victim and a blind pianist, Beckett ended up taking part in very emotional dramas rather than strictly flashy, tech-oriented stories as the scientist got inside (literally) his hosts and did his darndest to improve their situations. "The show speaks to the person we would all like to be — kinder, more compassionate," one homemaker said of it at the time. "There are so many layers of the show," another fan said. "Sam is like the boy next door, a superhero in everyman's clothes. The show's not fluff. It's a thinking person's entertainment."

And those thinking people made their thoughts known, burying NBC in letters when the network moved their show around the schedule too much, publishing newsletters, holding conventions and even buying a star for Stockwell on the Hollywood Walk of Fame. Even with low ratings, QL still managed to spin off properties into other media, including books and comic books, despite its often questionable future.

As far as Stockwell was concerned, hovering at death's door shouldn't have been anything new. After enjoying steady work as a child actor in such movies as Anchors Aweigh and Gentleman's Agreement, he'd dropped out of the business at 15, returned in his 20s to earn critical kudos in films like Sons and Lovers and Compulsion, then dropped out again to live the '60s bohemian lifestyle with pals like legendary party guy (at the time, anyway) Dennis Hopper. By the time he was struggling to find work and was introduced to filmmaker David Lynch in Mexico City in the early '80s, Stockwell was rumored to be dead. "This person looked familiar, but [I told myself] it couldn't be who I thought it was, and it made me feel a little nutty," Lynch said in 1990. "Then I realized it was Dean, and he was alive."

Lynch helped resurrect Stockwell's career, too, casting him in Dune and then signing him on for a legendary performance in Blue Velvet. After really making his mark in Married to the Mob, Stockwell was going strong — so strong that QL producer Don Bellisario (JAG) was shocked when the actor expressed interest in the second-banana Al role. But the Stockwell's logic was simple: "I wouldn't have to work myself to death and I'd have time to spend with my family."

Bakula, for his part, would've been happier had QL done better in the Nielsens, but he's proud of the work he did. "We all felt we were doing such good stuff yet we didn't get the recognition," he told Knight-Ridder/Tribune News Service in 1995. "As time goes by now and we're away from all the award things and all that stuff, you realize the show has so much staying power and has so much presence in the world, and that's worth more than anything."

Agreed. And as Enterprise captain Jonathan Archer, Bakula now has a chance to maintain his presence on a whole host of other worlds, too.