Metropolitan Opera general director Peter Gelb doesn’t gloat. But if he did, no one could begrudge him an “I told you so.” The Met topper has been the driving force behind his 130-year-old company’s decision to transmit live opera into movie theaters via satellite. The effort — which was initially greeted skeptically by many opera and exhibition-business insiders — is now in its fifth season, and the numbers speak for themselves.

Dubbed “Live in HD,” the project launched in December 2006 when the Met beamed Julie Taymor’s production of Mozart’s “Magic Flute” to 56 theaters in four countries. This season the number of theaters stands at more than 1,500 and the number of countries at 46 — Spain, Portugal and Egypt being the newest to join the group.

Last season, with 1,200 theaters in 43 countries participating, “Live in HD” sold 2.4 million tickets. And those nine transmissions — there are 12 this year — took in more than $48 million in B.O., about half of which went to the Met. The Met’s latest presentation, Nicholas Hytner’s new production of Verdi’s “Don Carlo,” which bowed Dec. 11, rallied some 100,000 opera fans to 850 screens in North America alone. (With foreign and upcoming repeat screenings included, worldwide attendance for this opera is expected to top 280,000.)

“I didn’t think it would work,” says Heidi Waleson, the Wall Street Journal’s opera critic. “I asked, ‘Why would anyone pay for this?’ Wasn’t I wrong. The really amazing thing is not only is it an audience builder, it’s also a new revenue stream, and that’s unheard of for a non-profit. So more power to them.”

When Gelb arrived at the Met in August 2006, highbrows were concerned that a veteran of the failing classical record industry was now heading the venerable, if financially challenged, company. (Gelb previously ran Sony Classical for more than a decade.) But his background as a freelance producer for Met’s TV broadcasts in the 1980s has served him well.

Despite the Met’s nearly 80-year history of continuous radio broadcasts, until Gelb’s reign the company had never embarked on a project that emphasized the visual, as well as the sonic, aspects of opera.

“I said to the board and unions that in order for the Met and opera in general to regain some momentum, we had to look at all the distribution platforms,” Gelb recalls. “We negotiated new agreements with the Met’s 16 unions so that we could capture live content and distribute it. What’s being seen in cinemas is just one part of that.”

Beyond the live transmissions, the Met also partnered with Sirius XM to create a 24-hour satellite radio station. In addition, the company developed Met Player, a subscription streaming service, and it releases opera performances from its archives on DVD through its own label and in partnership with Universal Music.

“We took a much more energetic approach,” Gelb says, explaining his multi-tiered strategy for expanding the Met brand. “The model was sports teams — the way they strengthened the bond with their fan base through maximum broadcast of their games. Instead of sating fans, this approach has only increased fan interest.”

The salient factor, Gelb maintains, is that the transmissions to screens in North America are live. “Opera fans are as fanatical as sports fans,” he says, “even if an opera’s conclusion is never in doubt. And audiences react as if they were in the opera house, even though they know that the singers can’t hear their applause. So we’re defying the trend of the individual entertainment experience.”

“Live in HD” arrives on the majority of movie screens via NCM Fathom, a division of National CineMedia, which operates the largest digital-content distribution network to movie screens in North America. “It’s an opportunity for opera fans to have a community experience at their local movie theater that’s convenient and affordable,” says Dan Diamond, Fathom’s VP. “And it’s an opportunity to see the Met live from Lincoln Center without actually being there. There’s a powerful synergistic experience that begins with the gathering of communities in movie theaters.”

Gelb suggests that it’s not just the Met and its fans that benefit. “Theaters are glad because we’re bringing in an older demographic,” he says. “We’ve proved that alternative content can draw an audience. Who would have thought that opera would be the (performing arts) leader here?”