Chinese micro-blogging site Sina Weibo rolled out a QR Code feature this morning for their 300 million plus registered users. From today every user can generate a customized QR Code for their account from their PC or from within the Sina Weibo Android or iPhone app. Sina Weibo is hoping that individual and corporate users will use the QR Code to promote their online activities and they specifically mention the printing of these QR Codes on business cards. A month ago the world’s biggest group messaging app the Chinese-made WeChat incorporated a similar feature for its 100 million plus users. There are over 1 billion mobile subscribers in China and one in four smartphones made will be sold there this year.