Messaging app firm Line swung into the black in 2016 on strong growth in advertising, which increased more than 50 per cent in Q4.

Line, a subsidiary of South Korea-based Naver, posted a net profit of JPY7.56 billion ($66.5 million) for the year ending 31 December, compared with a loss of JRY7.58 billion in 2015. Its revenue last year increased 17 per cent to JPY140.7 billion.

Its operating profit jumped ten fold to JPY19.9 billion in 2016, but operating income fell 68 per cent quarter-on-quarter in Q4, due to higher operating expenses related to increased hiring and payment settlement issues. The company said staffing costs would continue to increase as it expands, although it expects an operating profit in Q1 2017, Reuters reported.

Monthly active users inched up 1 per cent year-on-year to 217 million at end-December, but were down from 220 million in June.

Tokyo-headquartered Line, the most popular instant messaging service in Japan, raised $1.26 billion last July in an IPO. It generates most of its income from ads, mobile games and digital stickers, but is expanding into areas including ride-sharing, mobile payments, music and video-streaming. It also launched an MVNO.

Its major markets are Japan, Taiwan, Thailand and Indonesia. Japan accounted for 73 per cent of its revenue last year.

The company didn’t provide a full-year earnings forecast for 2017, but said Q1 revenue is expected to increase from last year.