(Telecompaper) The IP messaging service Viber reached 608 million registered users at the end of July, up from 408 million at the start of 2014. Unique users, based on phone numbers, totaled 400 million, versus 280 million at end-2013. The figures were reported by Japanese e-commerce group Rakuten, which acquired Viber earlier this year. The company said it's working on integrating Viber user IDs with its own customer ID system. The integration of the messaging platform is expected to help drive traffic to Rakuten sites and use of its applications and services. Rakuten also reported an increase in the number of users on the Kono e-books and content platform, to 20.9 million at the end of June, up 38.9 percent from a year earlier. Overall, Rakuten's revenues were up 8.3 percent in Q2 to JPY 138.3 billion, while operating profit fell 9.9 percent to JPY 22.2 billion, hurt by lower results at its stock market business and investments in new online services.