As the lone West End survivor of the dozen tuners that opened in 2006, “Wicked,” celebrating its fifth anniversary Sept. 27, looks to be chugging along as strongly as its Broadway counterpart, which after eight years, shows no sign of slowing.

But in the U.K., where “The Wizard of Oz” is far less of a cultural icon than in the U.S., much of the London success of the Emerald City redux comes down to the West End production’s groundbreaking use of online and digital marketing.

“To an extent, we were following Broadway’s lead,” says Jo Hutchison of marketing company Jo Hutchison Intl., whose credits include “Mamma Mia,” “Priscilla Queen of the Desert” and which handled the London launch for advertising and marketing company Dewynters. “But at the time, convincing everyone that musical theater fans would communicate with each other online was definitely an uphill struggle. Theater hadn’t really done that before in a major way. The digital marketing spend for ‘Wicked’ was higher than for any other musical.”

Ad dollars were shifted away from traditional avenues of major print and off-line locations, and online the show even moved well beyond the expected forum of theater-specific websites. Proof of its success is now highly visible on Twitter and Facebook, where the London production has around 40,000 fans who are constantly updated with the show’s every development on- and off-stage.

The digital strategy seems to be working at the box office: According to the show’s London executive producer Michael McCabe — who teamed with U.S. producers Marc Platt and David Stone on the Brit incarnation — the accumulated gross at the 2,292-seat Apollo Victoria is “in excess of £145 million” ($228 million). Its only rival for the weekly top financial spot is Disney’s “The Lion King,” which is in a similarly large auditorium.

“Wicked” also boasts year-on-year growth with its 2010 total of $47.2 million marking a 10% rise over 2009. This year is on target, McCabe adds, averaging in excess of $967,000 per week, up 7.5% compared to 2010.

(If that weekly gross seems low compared to Gotham totals, it’s because London ticket prices are significantly lower. The weekend top is $102 compared with Broadway’s $130. Moreover, London has far fewer premium seats, and they’re priced at $145, which pales beside $276.25 at the Gershwin.)

The London incarnation isn’t resting on its laurels: An additional specialist company, Think Jam, was brought on board earlier this year to handle digital PR and promotions.

“Theaters tend to speak to their core audience using expected theater-ish environments and websites,” says Think Jam commercial director Philip Rose. “That’s a closed group. We’re widening that out, working online with video content on broader entertainment websites and far beyond.”

With a client list including 20th Century Fox, Fox Searchlight, Universal Pictures and Warner Bros., the company applied its handling of movie releases and rollouts — exclusive placements of first-look packages on high-traffic portals, syndicating material to websites and blogs — to the similar needs of “Wicked.”

Although the company uses a film-centric approach, Rose highlights one major difference. “With a movie you have a strictly defined time period through pre-release to opening. For a long-running theater show like ‘Wicked,’ the campaign is about a continually ongoing dialogue. The social media activity surrounding it illustrates that it’s not about merely plundering people’s excitement for the show, but about building a relationship with them.”

Unlike plays, which only very rarely expect audiences to return for multiple viewings, tuners thrive on repeat business. In the case of “Wicked,” that’s boosted with “Ozmopolitan,” the show’s monthly newsletter sent out to the entire fanbase via direct email and social media, all of which is linked together. There’s also major outreach work to family websites and “mummy blogs” and placement programs with the educational sectors to capitalize on the tuner’s youth appeal.

Happy though he is with the marketing, McCabe remains clear-eyed about its potential.

“You can spend a lot of money and achieve something in the short term but marketing alone doesn’t turn shows around. We have been able to enhance a popular show. It’s the show itself that counts. That’s why were still here after five years.”