When “The Big Bang Theory” premiered on CBS, it was more like a quiet pop.

In its Monday 8:30 p.m. timeslot, the first of many for the versatile sitcom, the show attracted an average of 8.4 million viewers — a number that’s nearly doubled to 15.3 million over the five years the show has been on the air — and it ranked 41st among viewers among all scripted shows in primetime, fighting its way through the 2007-08 Writers Guild of America strike.

But CBS had faith in the Chuck Lorre comedy that had been in development for two years and gone through two pilots, so it ordered another season. In season two, “The Big Bang Theory” moved up to 19th among all scripted shows in total viewers, averaging more than 10 million.

In “Big Bang’s” sophomore season, CBS moved the skein to 9:30 p.m. as a lead-out from the Eye’s whopper hit, “Two and a Half Men.” That experiment was wildly successful, so 9:30 p.m. became “Big Bang’s” permanent home in season three.

It was there that “Big Bang” flourished. It ascended primetime’s ranks to become sixth among all scripted series in total viewers with 14.4 million, and scored a very healthy 5.3 rating in the 18-49 demo.

“It’s when the show moved to 9:30 p.m. that we really realized its full power,” says Peter Roth, president of Warner Bros. Television.

That success emboldened CBS to move the show again in season four, but this time to a much more risky 8 p.m. Thursday timeslot. The shift also offered plenty of reward, however. Thursday is the most lucrative night of the week from an advertising perspective.

“It was a risk, but one that we were ready to take, given our other development that season,” recalls Nina Tassler, CBS’ president of entertainment. “The show was gaining momentum and if it hadn’t worked, we had alternative moves to go to.”

“I was nervous when I heard about the move,” says Roth, “but I also thought it was smart. The show had clearly established itself and had a strong, loyal and growing audience. The clearest lesson I’ve learned over the 38 years I’ve been in this business is that audiences follow great shows no matter where you put them.”

“The Big Bang Theory” made the move effortlessly, though its numbers dropped a bit — ranking seventh among all scripted series, averaging 13.4 million viewers and scoring a 5.1 rating in the demo. But it won the time period and gave CBS a strong entry into the rest of its night.

With the series now in its fifth season, Roth believes the show will remain a powerhouse — both creatively and on the ratings scoreboard — for awhile.

“We are celebrating a series that is really just beginning to emerge: financially, creatively and emotionally,” says Roth.

On the move

Despite several timeslot moves, “The Big Bang Theory” managed to grow its already sizable CBS audience.

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