One weak spot on the three-hour comedy night on NBC Thursday, which resulted in pretty good ratings for both “The Office” and “Parks & Recreation,” seen by 8.2 million and 6.1 million respectively, was the measly 4.1 million who saw the pilot for the new “Perfect Couples.”

The show had theoretically premiered before.  After the finale of “The Sing-Off” last month, they threw on an episode and called it a “preview” that did just half as well as it did Thursday.

The actual debut showed it to be yet another variation of the prevailing sitcom premise featuring various couples at different stages in their relationships, from “Rules of Engagement” to “Better With You.”

And while it had the kind of things the other sitcoms had going for them – occasionally funny lines, temporary employment for pretty good sitcom people – it also seems a great misuse of one of its most prominent cast members, Olivia Munn.

A woman whose fame arose on cable, on “Attack of the Show” and now occasionally on “The Daily Show,” she is one of the stereotypes on “Perfect Couples,” but one that she agrees is the direct opposite of her real personality.

Her character on “Perfect Couples” is really perfect – straight-laced, preppy, proper, pearl-wearing – while the personality she perfected on cable is that of an anything goes guy’s gal, who can wisecrack, prank and do dares with the best of them.

At press tour she seemed even further removed from her old G4 self, with her long brunette locks cut short at the shoulders.

“It’s for a movie,” she said. She was about to shoot “I Don’t Know How She Does It,” a Sarah Jessica Parker vehicle about a multitasking woman, a film that also stars Kelsey Gremmer, Pierce Brosnan, Christina Hendricks and Seth Meyers.

“I cut it after shooting ended for ‘Couples,’ went on ‘Letterman’ and cut it more after that,” she said. It’s not something that worries her as much as it might her fans. “It grows back quickly.”

Munn’s career has grown as well, though none of her current TV roles, either on “The Daily Show” or “Perfect Couples,” shows her to be as comfortable as she was on “Attack of the Show,” where a series of new female partners to Kevin Pereira. Her notoriety there led to small roles in films such as “Iron Man 2” and “Date Night.”

“The fans are the only reason why I’m sitting here today, and I always give them credit,” she said earlier in the day at a pres panel. “I don’t consider that I’ve left them. I feel like they’ve put me on this ride, and they’re coming along for the ride with me.”

Munn says she’s “still very in much communication through my website, through Twitter. And I do fan meet-ups with them, and I’m very much in contact with them.”

And acting, she says, “is something I’ve wanted to do forever. And on ‘Attack of the Show,’ I had such a great time, and it was such a great experience, but you want to try to see if you can make some other dreams come true. And because of the fans and because of the support they’ve given me, I’ve been given these opportunities.

“I wanted to continue doing ‘Attack of the Show,’” she said. “But apparently you can’t do, like, four shows at once.”

“Perfect Couples” is on Thursdays at 8:30 p.m. on NBC.