NAB's Online Retail Sales Index for November found that online retail sales were up 62% over the month, compared to the same sales event the year before.

"From a shaky start earlier in the decade, this sales event day appears to be growing," NAB Chief Economist Alan Oster said. 

"The event has been gaining momentum since 2015."

The biggest drivers behind overall sales on the day were homewares and appliances, department stores and personal and recreational goods. Fashion, which normally represents a significant share of sales on the day, was more subdued this year.

"It is likely that these sales events are shifting the period when sales occur, without adding to total sales," Mr Oster said.

"Our data suggests that Black Friday represented almost 10% of total November online sales. In 2012, this figure was just over 4%."

Overall, NAB found that online retail sales were up 2.4% in November and by 9.6% over the year. 

"We estimate that in the 12 months to November, Australians spent $30.14 billion on online retail," Mr Oster said. 

The biggest growth in online sales was takeaway food, up by 163% on Black Friday compared to the same sales event the year before. 

The results come a day before the Australian Bureau of Statistics (ABS) is set to release its own retail data for November. Many economists hope a small rise will break the seven consecutive month drought of stagnant figures. 

Consumer spending growth fell to its lowest level since the Global Financial Crisis in September according to the ABS, with rate cuts failing to translate to discretionary spending. 

Early indicators suggest the recent bushfires may put a dampener on consumer confidence, which has returned to lows not seen since the GFC according to ANZ-Roy Morgan's weekly survey of consumer confidence.

ANZ expected the struggling retail sector to have bounced back in November mostly due to the Black Friday sales.

The retail downturn has hit companies hard, with women's fashion retailer Bardot today announcing it will shut the vast majority of its stores over the next two months. 

The fashion chain entered administration in November, joining a long line of retailers to do so last year as the sector struggled.

Australian winemaker McWilliams Wines also announced today it would be going into administration.