When “Dancing with the Stars’” Tom Bergeron was approached to host the reality series in 2005, he wasn’t exactly certain that a ballroom-dancing competition show was a slam dunk. Not only was it slated for summer, which at the time was a notoriously dead part of the programming year, but it was about a dancing style some might say would be better suited to PBS.

“When the concept was first presented to me, I thought, as many did within ABC, this is not going to fly,” says Bergeron. But watching the BBC show on which it’s based, “Strictly Come Dancing,” changed his mind. “I thought, ‘OK, this could be fun.’ It appealed to the part of me that grew up watching variety shows. I also love live television, and it had a sense of humor about itself that I really appreciated.”

Ten years after the show’s debut, Bergeron is happy to point out “you never know,” when it comes to concepts, and he credits the show’s constant innovation for keeping viewers coming back after 20 different seasons over the course of a decade.

That’s also what has kept the show on ABC’s schedule, even though it’s not attracting as large of an audience as it did in its earlier days. “The neat thing about reality shows is you get to reboot every season with a new cast,” says ABC’s Robert Mills, senior VP of alternative series, specials & latenight programming and the executive who supervises the series.

“Casting is the straw that stirs the drink, and the casting these last few seasons has been stellar. There has really been an emphasis on storytelling, and the new pros who have been injected in the mix have really breathed some fresh air into it. It’s really about an engaging cast with stories and journeys.”

Though the format continues to evolve for audiences, the changes behind the scenes keep anyone from becoming complacent. Showrunner Rob Wade, who’s been with “DWTS” since the beginning, took over from longtime showrunner Conrad Green in season 19, but he says he didn’t come with any plans to veer from the heart of the concept.

“People call it competition-reality, but the truth is that it’s like all good reality — it’s real,” Wade says. “They actually do learn to dance, and they actually have to perform.”

Five-time mirror-ball trophy winner Derek Hough, who has coached some of the show’s biggest breakout stars and was injured right before the show’s 10th anniversary special taped, says the series’ enduring appeal lies with the fact that it’s live and anything could happen. Seeing somebody who really is putting themselves out there and doing something kind of scary and uncomfortable, when you see them accomplish it, that moment is such a wonderful thing to watch,” Hough says.

The pitfalls of live TV keeps everyone on their toes, in front of and behind the cameras. “There’s hundreds of technical issues that could go wrong, so inevitably one does. Sound boards go down, lighting boards go down, screens go down,” Wade says. “One of the most memorable is when we didn’t have any lights and we were counting down to show, and suddenly they all sort of flickered on at the last minute. It’s a constant battle every week just to get on-air, but thankfully, we’ve got an incredibly professional team of people.”

Wade says his biggest challenge in keeping “DWTS” vibrant for viewers is similar to the challenges of anyone producing TV: changing viewership. “People are cord cutting, and people are consuming media in a different way. My mother is 75 years old, and she spends a lot more time on the Internet and on Facebook than she ever used to. People have only got so many hours in a day, so as a producer of any television show, you’re faced with that issue.”

After a record-low season opener in key demographics this season, the show has been on the uptick, getting a big boost from its popular Disney-themed night. Although Mills admits that the Nielsen numbers still rule, “DWTS” has a healthy amount of social-media engagement.

“It’s always a great thing to be able to show that we are upscale, we are incredibly social, there’s a lot of engagement,” Mills says. “At the end of the day, our Nielsen report card is the biggest thing, but those other things absolutely help. You want to be involved in a show that people are talking about.”

“We’ve expanded hugely on a digital level,” Wade adds. “Our YouTube channel is exponentially bigger than it ever used to be. Even if they’re not coming to the show every week, they’re still invested in the show and following the story of the show.”