Nike sales up since Kaepernick ad launched - report

Nike's ad campaign featuring controversial former NFL star Colin Kaepernick appears to be working.

Sales in the days following the ad's debut are up 31 percent on the same time last year, according to commerce tracking company Edison Trends.

"There was speculation that the Nike/Kaepernick campaign would lead to a drop in sales but the data does not support that theory," the company said, based on its online sales.

Edison came up with the number by analysing purchase receipts from 3 million sales over September 2 to 4, from 200 different retail outlets and Nike's own online store.

Kaepernick, the star of the campaign, infuriated US President Donald Trump with his refusal to stand for the national anthem. When the Nike campaign was launched, supporters of the President uploaded videos of Nike products being set on fire.

Mr Trump himself said Nike was "getting absolutely killed with anger and boycotts".

"I wonder if they had any idea that it would be this way?" he wrote on Twitter.

Marketing company Apex estimated the news coverage of the risky Kaepernick campaign was worth as much as US$43 million in advertising, Fortune reports.

Nike's shares sit about 1 percent below where they were before the advert debuted, and about 60 percent higher than a year ago.