Next Tuesday this will be a reality as 150 retailers, including Myer, Target, Westfield and Dick Smith, come together in an Australian online first that mimics America's biggest shopping phenomenon, Cyber Monday.

With an estimated 1 million people expected to walk through the ''virtual doors'' of the Click Frenzy website, there are fears some shopping sites will crash.

''Look, that is always a risk,'' the co-founder of the website, Grant Arnott, said. Big and small retailers have expressed their concern at how their sites will cope with the expected unprecedented amount of traffic over the 24 hours, he said.

Newer websites will be most at risk of collapse with all retailers encouraged to update their online infrastructure to cope with demand, Mr Arnott said.

He expects the event will set a new online sales record for Australia. ''We're expecting a record volume of transactions on the day. It's hard to say exactly how much but we expect it will be tens of millions of dollars.

''As with Boxing Day sales, we want virtual queues waiting for the virtual doors to open.''

More than 150 retailers have signed up for the promotion, slashing online prices - by up to 90 per cent - for 24 hours.

The executive director of the Australian Retailers Association, Russell Zimmerman, said while there could be technical ''glitches'' with the promotion, it would help retailers better understand the virtual space.

''There are 66 per cent of retailers who have a website but don't sell online,'' Mr Zimmerman said. ''The sector is changing.''

David Jones - which only launched its own website last Monday - will be keenly observing the online event from a distance.

''We will consider possible participation in the future once we have assessed the performance and customer cut-through of Click Frenzy,'' a spokeswoman for David Jones said.

Mr Arnott said the event had been scheduled to begin at 7pm to capitalise on the ''couch commerce'' phenomenon - the increasing trend for consumers to shop via iPads, laptops or mobiles while watching TV.

Other participating retailers include Saba, Sportscraft, Dan Murphy's, Kogan, The Iconic, StyleTread and Booktopia.

In America, Cyber Monday, which was launched in 2006 and offers online sales from more than 700 retailers, now attracts 10 million shoppers.

smh.com.au