Hong Kongers snapped up HK$500,000 ($65,000) in Bitcoin vouchers on Thursday to mark the Lunar New Year in what organisers said was the biggest ever giveaway of the currency -- though some were confused about how to use it.

Young women in short skirts handed out 50,000 coupons worth HK$10 around the city all day and into the evening. Vouchers were tucked into the red envelopes ubiquitous during the new year festival, embossed with the Chinese word for "luck" in gold.

The envelopes -- known as "lai see" or "red pocket" -- usually hold cash and are given to family, colleagues and anyone else who deserves a thank you.

Hong Kong Bitcoin exchange ANXBTC said the giveaway was the biggest ever and hoped the "digital lai see" would be a simple way to introduce Hong Kongers to the currency.

"There's a lot of information out there but for someone who's not so tech savvy it takes some time for them to get into it," ANX chief executive Ken Lo told AFP.

Recipients scan the voucher's QR code which takes them to a website where they can set up a Bitcoin account just by entering their email, said Lo.

"There hasn't been any fighting because we have a lot (to give away), but there are a lot of people -- even in our office they're lining up," said Lo.

But while shoppers in bustling Causeway Bay were happy to get a freebie, many were still confused as to what to do with it.

"I don't know anything about it," said estate agent Chan Wing-fung, 44, who asked an AFP reporter to explain it to him.

"It's not a currency with which I could control my losses or gains," said another recipient, who gave his name as Andrew.

"It's not really useful for me."

Lo admitted the city was "behind the curve" on the virtual currency.

"There is so much money and big business and finance that people don't need to look anywhere else. They don't need to innovate," he said.

"It needs to get to the level where you walk into 7-11 and you pay the cashier and you get the Bitcoins."

Bitcoin was invented in the wake of the global financial crisis by a mysterious computer guru using the pseudonym Satoshi Nakamoto.

Unlike other currencies, it does not have the backing of a central bank or government. Instead, the units are generated by a complex computer algorithm designed by one or more anonymous people in 2009.

The volatility of its value has drawn criticism and the unregulated currency has also been linked to various kinds of criminal activity.