Neal Justin / (Minneapolis) Star Tribune

“Smash” is decisively not living up to its title.

It didn’t start out that way. The NBC series, which revolves around the making of a Broadway musical about Marilyn Monroe, premiered in February to 11.5 million viewers, a godsend for a network whose prime-time lineup is holding on by a thread, or, more specifically, a mindless singing competition (“The Voice”).

NBC quickly renewed “Smash” for a second season and executives almost certainly began plotting “Law&Order: Broadway.”

Then fans started abandoning ship. The show now draws about 6 million a week.

It can only get worse. Creator Theresa Rebeck won’t be returning next season, and a changing of the guard this early in a show’s run is never good news. And then there’s the question of what happens when the show’s fictional musical, “Bombshell,” premieres, an event that occurs during the May 14 finale.

So what went wrong so quickly — and how can networks avoid making this mistake again? A review of nearly all 15 episodes and a look back at other fast-fading series suggest the following tips:

• Don’t oversell yourself. “Smash” had so many ads leading up to its premiere, you’d think Katharine McPhee was running for president. Sure, that helped the premiere, especially because the campaign was tied to NBC’s airing of the Super Bowl the previous night. But with heavy promotion come weighty expectations, ones that few shows can uphold.

Audiences don’t need Oscar-winning advisers and relentless publicity. Just ask the folks from “Seinfeld,” “CSI” and “Cheers,” shows that actually benefited from soft launches. Viewers don’t want to be told what to love.

• Don’t make us haters. The biggest debate among “Smash’s” dwindling fans isn’t about which character is their favorite, it’s about which is most annoying. The leader of the pack appears to be Ellis “I just heard something” Boyd (Jaime Cepero), a two-faced assistant who’s such a weasel he makes Eddie Haskell look like Captain America.

My personal vote goes to the musical’s producer, Eileen Boyd, if only because she’s played by Anjelica Huston.

• Don’t try so hard. The theater world may be fraught with massive egos and backstage betrayals, but “Smash” takes it way too far. A kid running away from home because — gasp! — his parents might be separating? Check. Switching Marilyns as often as most people change their toilet paper? Check. Watching your lead actor abandon the show two days before the curtain rises? Check.

And let’s not forget the unintentionally hilarious Bollywood scene. It may be the most maligned fantasy sequence since Ally McBeal boogied with a baby.

You can admire a series with so much ambition, but that doesn’t mean you have to love it. Nonetheless, “Smash” will probably have a second chance next season — a rare luxury these days, and only because it’s on a fourth-place network. Let’s hope its producers use that opportunity to build a better “Bombshell,” and not a bigger bomb.