If you haven’t come across George Takei lately, you might be living under a digital rock.

The former “Star Trek” actor has, over the past five years, morphed into one of social media’s more prominent figures, posting everything from funny cat photos to impassioned support for LGBT rights. He has more than 6.2 million Facebook fans, plus another 1 million Twitter followers eager for the latest intel; in contrast, the “Star Trek” franchise’s official Facebook page counts less than 3 million fans.

It’s an unusual route back into the spotlight for a man whose greatest claim to fame used to be his vintage gig as Lt. Commander Sulu. But perhaps even more surprising is the fact that his Internet renown came about in large part due to his link to a Broadway-targeted musical — one that hasn’t booked a Main Stem theater yet, but already has in place an active social-media strategy of which Takei is the most significant component.

Visitors to the actor’s Facebook page will land on a cover photo that prominently features a promotional image for the tuner “Allegiance,” with Takei posed alongside co-stars Lea Salonga and Telly Leung. The musical, a love story set against the backdrop of a Japanese-American internment camp during WWII, isn’t just a job to him. His own childhood memories of life in such a camp inspired the show, which grew out of a chance 2008 encounter between Takei and startup entrepreneur Lorenzo Thione, the lead producer of “Allegiance” and its co-book writer.

Thione — who cashed in when the search-engine company he helped found, Powerset, sold to Microsoft — suggested Takei increase his social-media presence in service to the show. “We said, ‘George, why don’t you start a Twitter account?’ ” Thione says. “He surprised us by how engaged he is, with this dry humor paired with civic duty — and Twitter and Facebook started responding really well.”

Takei recalls the process as one of trial and error. “We started with sci-fi topics, given my fanbase at the time, but I noticed that the funnies, the humorous, the comic memes (like LOLcats) are what’s shared the most. I grew the following with humor, but once I did, I started introducing more serious issues” — such as LGBT equality, for one, as well as the story of the U.S. internment camps.

Thione says Takei’s digital presence has sizable benefits for “Allegiance,” which still holds the box office record as the highest-grossing show in the history of San Diego’s Old Globe, where it played a tryout run in 2012. “When you have a situation like ours, a completely original show about a potentially dark subject with a new creative team, you ask, ‘Is there an audience?’ Building out the social media answers that question.”

Scrolling down Takei’s Facebook timeline reveals periodic shout-outs to the show’s recently announced priority-access seating offer. Producers aren’t selling tickets, since there aren’t any yet to sell, but for $5 a fan can buy what amounts to a place in line to purchase seats once the Broadway box office presumptively opens. (The priority pass also entitles buyers to a digital download of the cast recording.)

It’s all aimed at helping the musical, with tunes by Jay Kuo and a book co-written by Marc Acito, remain a topic of conversation while it searches for Broadway home. “One of the things that’s death for a show is if no news happens for a long time,” Thione says.

Which points out another reason to amass an online following: “It’s essential to persuade nervous theater owners,” Takei says. “We’re saying they don’t have to be skittish about booking a show that takes on a dark chapter in American history. With this priority access, we’re showing them dollars and cents.”

It’s too soon to fully gauge response to the priority-access initiative, but everyone onboard the project has deemed social media an important component in helping the tuner take its next step. “It’s a vital part of this enterprise,” says Takei. “The ‘Allegiance’ enterprise. Not the Starship Enterprise.”