The Click Frenzy online sale has been derided as an "epic failure", with even the industry's staunchest supporter admitting shoppers and retailers will have been disappointed.
The Click Sale site, which promised bargains from dozens of big names including Myer and Dick Smith, went live at 7pm (AEDT) on Tuesday, but promptly crashed under the weight of traffic.
Access was sketchy all night and even on Wednesday morning the site still appeared beset by problems.
The situation sparked an angry backlash from disappointed shoppers.
"Seeya ... unsubscribe ... epic failure," one person wrote on Click Frenzy's Facebook page.
"Get your file servers prepared before you promote crap."
There was also a "Click Fail" Facebook page set up and a YouTube video featuring Hitler mocking the sale.
Click Frenzy founder Grant Arnott apologised on Facebook but was unable to explain exactly what the problem was.
"Firstly, I would like to issue an apology to anyone who has been inconvenienced and frustrated by the technical issues relating to the inaugural Click Frenzy 24-hour online sale," he wrote.
"The technical directors, developers and infrastructure specialists involved in this inaugural event are working to get to the root of what occurred with the wave of traffic at 7pm."
Australian National Retail Association CEO Margy Osmond said there would be a "level of disappointment" and conceded some first time online shoppers could be turned off by the experience.
But she insisted there were positives, particularly for retailers such as David Jones and Dell, which held separate sales not linked to the Click Frenzy website.
"It's unfortunate that the organisers of Click Frenzy have had these problems," she told AAP.
"I think there might be a level of disappointment among a number of the retailers.
"But then there are others who made the decision to do it as a stand-alone exercise and they've done extremely well."