"I want to see glitter and sequins and feathers," shouts American actress Lily Tomlin as she pumps up revellers ahead of Sydney's famous and irreverent Gay and Lesbian Mardi Gras.

"I want to see you basking in your own glory!" she yells as the gay pride parade, an annual event which has enjoyed a growing international profile in recent years, kicks off under rainy skies.

Comedian Tomlin was a celebrity guest at this month's Mardi Gras and one of thousands of foreigners joining what has become a major cultural event in the Asia-Pacific.

"It's welcoming, it's fun and entertaining and slightly irreverent," says Mardi Gras chief executive Michael Rolick of the raucous parade of some 8,500 people - dressed as everything from bikers to angels - which was watched by tens of thousands more who lined the streets.

The parade is known for its outrageous costumes, and scores of participants dressed as brides and grooms in support of gay marriage, while others wore cheerleading outfits, chain mail, hot pants or, in some cases, not much at all.

Rolick believes that for the past 10 or 15 years the parade has been Australia's best known cultural event, and a must-see for tourists along with the Sydney Opera House and Harbour Bridge and Bondi beach.

"There aren't too many gay pride festivals which happen at night time at summer and stop the middle of the city like this and have the support that Sydney does and I think that that's something they want to experience," he said.

Sydney is best known for its spectacular New Year's Eve fireworks but the gay pride march - one of the world's biggest - also draws crowds, pulling in 22,000 foreign tourists in 2010.

Officials say the pink dollar is also lucrative, with those who come to Sydney for the Mardi Gras spending on average more than other tourists and depositing Aus$30 million (US$30.4) in the state economy each year.

The event held its own during the global financial crisis, and indications are that its audience is being increasingly drawn from Asia, although the United States and Britain are the largest markets by a big margin, accounting together for about 40 percent of foreign visitors.

Rolick said the two main markets were followed by New Zealand and western Europe but acknowledged there was "an increasing interest from our own backyard."

"The tourist numbers from that part of the world (Asia) are starting to increase," he said, but added that foreigners have long taken part in the march, which has been a feature of Sydney for more than 30 years.

Among the Asian participants this year was the famous transvestite group Tiffany's Show Pattaya, whose exquisitely adorned models danced on a giant peacock float which ended the parade.

"This was something we've talked about for a few years," said the group's creative director Ken Smith, adding that Sydney's Mardi Gras was well-known in Thailand.

The Mardi Gras began as a 'fun' human rights protest in 1978 - but police cracked down heavily on marchers and more than 50 were arrested in the brief riot which followed. But the event helped bring legislative change, including the decriminalisation of homosexuality in New South Wales in 1984.

Rolick says it also helped bring the community together during the worst days of the HIV/AIDS crisis in the years that followed, but had lost none of its relevance by 2011 as it highlighted calls for same-sex marriage in Australia, which bans gay marriage.

"The parade is very much an amplifier, like a microphone, for what our community wants to say," he said.

"If you look at the event over the years, that has gone from 'we're equal and we're not criminals'... to not stigmatising us with HIV, to changing the age of consent, and the right to same-sex marriage equality."

But the tone is always light, with this year's march featuring a huge figure of Prime Minister Julia Gillard - who has said she believes marriage should only be between a man and a woman and who remains unmarried herself - in a bridal gown.

Peter Murphy, who took part in the first Mardi Gras and has been involved in many parades over the years, says the event has always been "a big party."

"It began as a Mardi Gras, it wasn't so much an act of defiance as a way to shift from a fairly routine type political protest to something that was more cultural and much more open and disarming," he said.