When Kakao Went Down, Everyone Flocked to Line: 'Just for 3 Days'

KISDI, Analysis of Changes in Mobile App Usage Behavior
Promotional Ads Boost New User Inflow for Competitor Apps like Line
Data Center Fire Causes Initial 'Flash Effect'

Last October, when Kakao services were paralyzed due to a data center fire, the usage of Line temporarily increased. Users perceived Line as an alternative service to KakaoTalk and chose Line over Telegram, which generally has higher average usage. However, this effect was concentrated only in the first three days following the incident, and the KakaoTalk user departure effect disappeared thereafter.

Recently, the Korea Information Society Development Institute (KISDI) released a report titled "Mobile App Service Disruptions and Changes in Usage Behavior Due to Communication Disasters," which includes these findings. On October 15 last year, around 3 p.m., errors occurred in major Kakao services including KakaoTalk, and these issues continued for five days. Kakao declared that all services were restored as of 11 p.m. on October 20.

Competing companies attempted to attract users through advertisements for their mobile messengers after news of the KakaoTalk outage spread.

Line posted an advertisement at the bottom of the Naver portal with the phrase "Use the global messenger Line when urgent contact is needed." The financial service Toss displayed an ad at the top of its app stating, "Toss also has a chat feature," to attract new users.

In fact, on the morning of October 16, the day after the Kakao service disruption, Line ranked first in the Apple App Store's free app popularity chart.

According to the report, analyzing the mobile app usage of about 8,000 users showed that the average KakaoTalk usage on October 15 (Saturday) and 16 (Sunday), when the service disruption began, decreased by 21.9% and 13.2%, respectively, compared to usual.

During the same period, the average usage of text messaging, Line, and Telegram?which serve as messengers?increased compared to the average of other weekends in October. Users utilized other messenger apps as substitutes for KakaoTalk.

Yoon Sung-wook, a KISDI research fellow, stated, "Although both Line and Telegram usage increased, statistically significant usage growth was observed only in Line," adding, "It can be inferred that users perceive Line as a substitute app for KakaoTalk."

Line Friends Hong Kong Langham Place Store

The daily average usage time for messenger apps was 1,472 seconds for KakaoTalk, 23.4 seconds for Telegram, and 7.6 seconds for Line, with Telegram's usage time more than three times that of Line. However, it is notable that users who left KakaoTalk after the service suspension migrated to Line rather than Telegram.

Research fellow Yoon analyzed, "Users recognized Line as a KakaoTalk alternative service focusing more on convenience and social networking features rather than security and privacy."

The influx to Line was significant only during the first three days after the incident, and this effect gradually diminished over time. Yoon explained, "Although the migration to other apps was temporary, consumers downloading competitor apps increased the possibility of future switching to substitutes."

Meanwhile, analyzing mobility app usage showed that on October 15?16, the daily average usage times for KakaoMap, KakaoNavi, and KakaoT were 25.8 seconds, 37.0 seconds, and 4.7 seconds, respectively, representing decreases of 29.0%, 39.4%, and 26.3% compared to other weekends in October.

The KakaoT user departure effect benefited its competitor UT (Uti). UT's average usage on October 15?16 was 0.336 seconds, showing a significant increase of 62.5% compared to the other weekends' average of 0.128 seconds.

The average usage times for Naver Map and T Map on October 15?16 were 74.5 seconds and 327.8 seconds, respectively, showing little difference from their averages on other weekends (74.9 seconds and 329.6 seconds).

Research fellow Yoon advised, "As public dependence on platform services has increased following digital transformation, service providers need to focus on ensuring service stability and preventing various disasters."