WeChat’s monthly active users were 355 million in Q4 2013, a 121% year-over-year increase and 6% quarter-over-quarter, as its parent company Tencent reported today. Unlike many other mobile services, the company doesn’t count login as an active action. Active users under its standard should have sent out at least a message or participate in a transaction in a month.

Tencent has stopped reporting total registrations and overseas users. But the company disclosed that USD100-200 million were spent in 2013 for marketing WeChat overseas. The management expect a similar amount of money will be spent there in 2014.

A total of RMB600 million (a little less than $100 million) was generated from mobile games on Mobile QQ and WeChat in the quarter. Mobile games hadn’t been added onto the two mobile apps until August last year. The quarterly ARPU of smartphone games is 60-70 yuan ($10-11) .

There were still 808 million monthly active users of QQ IM, Tencent’s flagship product, in the same quarter and 625 million of Q-zone, the Facebook-like social service of Tencent.