Tokyo's export curbs against Seoul in July prompted South Koreans to start a voluntary boycott movement called 'NO NO Japan'.
Those taking part stopped buying Japanese products and refrained from taking trips to Japan.
Data released Monday by Statistics Korea show the purchase boycott movement has become more evident on the web.
The total value of Japanese goods bought online by South Koreans dropped in the third quarter to about 41 million U.S. dollars, an on-quarter decrease of almost 26 percent, the biggest decline on record.
Given that total online purchases by South Koreans abroad saw a 21 percent on-year increase over the same period, the impact of the 'NO NO Japan movement' is clear.
It's also the first time that the on-year growth rate of Japanese goods bought online by South Koreans over a three-month period did not crack the 10-percent mark.
In fact, the increase on-year was only 2.3 percent.
An official at Statistics Korea said the boycott did play a role.
Kan Hyeong-woo, Arirang News.