"We can tell because their charging address was overseas but they were having it sent to them in New Zealand, and it only started happening since the World Cup began," she said.
"This is the first time that I've seen this."
Sales generally lift whenever New Zealand features in international media reports.
"Particularly when there's Maori things, they see that and there's always a great interest in Maori culture and they will look online to see what they can buy," Ms Armstrong-Jennings said.
Camping ground owner Kevin Lloyd has also been on the receiving end of an increased level of foreign spending.
Mr Lloyd, who owns the Top 10 Holiday Park in Whangarei, said his guest nights were up almost 30 per cent on the previous year's September figures.
Interestingly, but perhaps not surprisingly, Mr Lloyd said most of his guests in the past month have been foreign men in campervans.
"They're all very patriotic, they've got country flags on the inside of their windows," he said.
"I have to say they've been so well behaved.
"I was actually expecting a few problems but I've had no problems whatsoever."
Mr Lloyd said the visitors seemed to come in waves according to their nationalities, normally during the weekdays rather than at the weekend.
Up in Kawakawa, Marty Edwards has also benefited from the rugby tourists.
Mr Edwards, aka The Coffee Guy, parks his mobile coffee trailer in a carpark beside the turn-off to Paihia.
"There's certainly heaps of campervans going through," he said.
"I've done pretty well with espressos with the likes of the European visitors."
Estimating his business has been boosted up to 30 per cent during the Cup, Mr Edwards said he had been happiest with the feedback in his visitors' book.
"I've got comments in my book saying 'best coffee in the north', and one said 'finally a good coffee in New Zealand'."