In July this year, Japanese social networking app Line had 200m registered users. Now it has 300m. That’s a startling 100m new users added in just four months, at a time when the company is aggressively expanding worldwide. At a press conference to announce the new milestone – reported on by TechCrunch – Line said it’s “growing steadily” in Spain, Mexico and Latin America, while starting to market its service more in India, Turkey and seevral western European countries. The caveat, as ever with Line, is that it only gives out numbers for its total registered users – people who’ve signed up and tried the service, rather than those who are still actively using it. While 80% of registered users in its homeland are active, it’s distinctly unclear how that ratio falls overseas. TechCrunch points out that the biggest rivals, WhatsApp and WeChat, both give monthly active user numbers (350m and 272m respectively), so how Line compares is hard to discern. Some Western artists are building followings though: Paul McCartney now has 7.7m followers on Line, while Katy Perry has 2.2m.