Retail therapy may be slow and down, but credit card transactions during the 2012 Boxing Day Sales nonetheless have increased by as much as 30 per cent for the National Australia Bank, it said on Thursday.

During the Wednesday mad dash for super huge discounts, NAB said it processed a total of 3,839,518 ATM, EFTPOS and debit and credit card transactions, at a peak transaction rate of 100 per second, versus the 2011 record of just below three million, at a peak rate of 80 per second.

Consumer watchdog Choice's Ingrid Just surmised the jump in credit card transaction usage was spurred by people moving more into online shopping which, of course, requires a credit card if they wish to purchase anything. That, plus Australians are shying away from carrying lots of cash and using more of EFTPOS.

"Bricks and mortar stores - some of the big department stores like Myer and David Jones - are really throwing a lot of money at their online business. They were offering Boxing Day sales on Christmas Day in the evening [online], and really using that as a foot in the door," Ms Just was quoted by The Sydney Morning Herald.

"I don't think we've seen that before. Additionally, we're seeing non-retail businesses, like airlines, starting to get into the Boxing Day sales through their online channels. The traditional door-busting sales have started to bleed into online in a serious way."

Bruce Mansfield, EFTPOS chief executive, likewise said they debit and EFTPOS to continue through the festive period this year.

"Using EFTPOS for purchases at this time of year helps many Australians take control of their spending by enabling them to access their own money at the checkout," he said.