Retailers shouldn't let a holiday spending slump in Canterbury and Auckland scare them.

Digital payment company Paymark says the centres are seeing the smallest sales growth in the country - with Canterbury having just a 1.6 percent growth in sales, and Auckland 1.9 percent.

This is compared to regions like Wanganui and Palmerston North - which are seeing upwards of 8 percent growth.

Head of digital payments Darren Hopper says there's a good reason.

"Areas where you've got population, people are probably spreading that spend over a longer period of time. I think we'll see that sort of spend being distributed, and we've still got a week of Christmas shopping to go."

The trends suggest that Kiwis are getting their Christmas shopping done earlier.

Hopper says this year in particular, Black Friday and Cyber Monday sales have had a huge impact.

"When we look at transactional data nationally for that week, you can see a significant uplift from the previous year, so I think all that advertising for Black Friday and Cyber Monday is doing it's job."

He told Larry Williams that it's the first time we're seeing these sales having a big impact on New Zealand, with thisa Black Friday bigger than Boxing Day last year.

However, he says that it's the calm before the storm.

"This time last year, December 21st Kiwi's spent just under $1.1 billion. We expect to see this year somewhere near that figure."

Hopper says it'll be interesting to see what impact the sale days will have on holiday spending in years to come.

In recent weeks, Hopper says we've seen a pick up in the food and drink industry.

LISTEN TO DARREN HOPPER TALK WITH LARRY WILLIAMS ABOVE