LOS ANGELES (Reuters) - In May, two months after the release of his song Blurred Lines, pop singer Robin Thicke performed the soon-to-be megahit on NBC's TV singing contest The Voice.

That performance with collaborators Pharrell Williams and rapper T.I. helped catapult his single 42 spots to No. 12 on Billboard's Hot 100 chart the following week. It also tripled the previous week's downloads to 206,000. The song rose to No. 1 on the chart in June for a 12-week run in the top spot.

Although The Voice may not be the most-watched singing contest on television and has yet to launch a star of its own, the show has become one of the music industry's most coveted promotional platforms with its influence far outpacing Fox rivals American Idol and The X Factor, music and TV experts say.

"It continues to be a launching pad and a shot of steroids for certain songs," said Joe Levy, editor of trade magazine Billboard whose annual poll of industry experts published this week showed a big jump in influence for the show.

He points to the recent performance by one of its judges, Christina Aguilera, singing Say Something with pop group A Great Big World. It helped the song claim the top spot on Billboard's digital songs chart last week.

The Voice, which airs twice a week and draws about 12.7 million viewers per episode, ranked as the sixth-best venue for promoting music up from No. 37 in 2012, according to the magazine.

Meanwhile, a live performance on American Idol, which can still best The Voice in attracting viewers, fell to No. 60 from No. 17, and Simon Cowell's The X Factor did not make the list of 75.

The Voice actually made the list twice. When a contestant performs an artist's song, that type of promotion was good enough for No. 56 on the list.

Part of the winning mixture for The Voice and the music industry has been the show's ability to distinguish itself as a music-first competition where everyone plays nicely, Levy said.

"'The Voice is really about professionals," he said. "It's really in that sense about building or restarting careers. 'Idol' hews closer to its talent-show roots and, frankly, people react to the fact that 'The Voice' is positive."

ALL ABOUT THE JUDGES

That is an unusual characteristic in the reality TV landscape where much of the focus is on conflict. Part of the appeal that American Idol built when it drew more than 30 million viewers for its finale in peak years of 2006-07 were its "jaw-dropping" failures, Levy said.

Another key to success of The Voice has been one of the problems that has plagued Idol and The X Factor in recent years: getting the personalities on the judging panel right, said Eric Deggans, the TV critic for National Public Radio.

The show's panel is led by Maroon 5 singer Adam Levine and country singer Blake Shelton in both fall and spring seasons, while singers Christina Aguilera and CeeLo Green serve in the fall, and Colombian pop star Shakira and R&B singer Usher in the spring.

"What people like about The Voice is that the judges, at least on camera, get along," Deggans said, noting that ratings for The Voice tend to dip as the season moves along and the focus is put more on the contestants.

"When they've tweaked the show, they've tweaked the show to keep them involved for longer throughout the competition," Deggans added.

Idol and The X Factor have suffered in part because of strife or poor chemistry on their panels on which they spend tens of millions of dollars in salaries, Deggans said.

Pop singer Britney Spears received poor reviews for her apparent lack of interest while on The X Factor last year, and a feud between judges Mariah Carey and Nicki Minaj ran throughout Idol's spring season. All three judges have since left.

Although Idol can still command more for advertising rates than The Voice, David Campanelli, a senior vice president at Horizon Media, said the NBC contest has been able to capture the popular culture buzz its rival once had.

"If it was all things equal, you'd pick The Voice because people are talking about that, and you want to associate your brand with that."

Tags: Adam Levine The Voice Blurred Lines robin thicke