Ironically, it comes at a time when the broadcast networks are struggling more than ever to develop sitcoms that survive even one season.

How “My Boys” fares tonight could be telling. Last Tuesday, its second outing, the series was watched by 907,000 viewers in the 18-49 demographic, according to Nielsen ratings. While down 300,000 viewers from its premiere, the sitcom still did better than the handful of original sitcoms that have premiered on cable networks over the years.

Its premiere was watched by 1.25 million 18-49 viewers, comparable to the audience for some of TBS’s biggest hits, like reruns of “Family Guy” and “Everybody Loves Raymond,” and it pulled a bigger audience than repeats of “Sex and the City,” the former HBO hit that's the inspiration for “Boys.” The show centers around a female sports writer who narrates each episode, as journalist Carrie Bradshaw did in “Sex.”

Steve Koonin, president of Turner Entertainment Networks, says it will take a few more weeks before he's comfortable calling it a success.

“We look for critical respectability, and in comedy that’s extraordinarily hard,” he says. The network is also gauging advertiser demand, which Koonin says has been strong. "The third thing [we look for] is ratings growth, and that will be decided over the entire run.”

Despite its second-week slump, “My Boys” is outperforming FX’s “It’s Always Sunny in Philadelphia,” perhaps the highest-profile live-action original comedy on cable. It wrapped up its second season in August with an average 832,000 viewers in the 18-49 demographic.

Meanwhile, TBS’s new late-night comedy “10 Items or Less” is also doing well, though with much smaller numbers, in some demos beating stiff competition in Comedy Central’s “Daily Show.” Its second episode two Mondays ago averaged 811,000 viewers in the 18-49 demographic and 560,000 among 18-34s. “10 Items” was up 9 percent over its premiere in 18-49s and 3 percent in 18-34s.

Part of the early success of the two new TBS series could be the absence of sustainable comedy on broadcast.

“People are realizing that this is a network that programs comedy,” says Jordan Breslow, director of broadcast research at MediaCom. “And because the [broadcast] networks are having such a hard time with comedy, I think viewers who are missing the genre and just want to laugh are looking for an alternative.”

TBS is already plunging deeper into originals, with five other comedies in development. Among these is “Imperfect Union” with George Wendt from “Cheers,” which is being produced by “Will & Grace’s” Eric McCormack.

“You have to define your brand and deliver against it,” says Koonin. “We use acquired programs to build a foundation, but we need to use original programming to bring more people to our network, and to make the network attractive to advertisers and cable affiliates.”