[zhte415]

Every local company I've seen in China run themselves to an extent on WeChat.

A group chat for all employees, a group-per-team, ad-hoc groups for ad-hoc teams. It is assumed to be faster (people check more regularly) than email, less formal, more direct. And the boss can see everything (given they're in the group). Great for teams that want to look busy. I dislike it, as looking busy is different from being busy, but this is a large part of the mainland China work-ethic.

For international companies, megacorps in particular, it is not used officially, but still often gets used, with a disturbing amount of client-specific information leaking that the head-office would strictly discipline should they know, but they don't.

To edit: This was always possible before with QQ, and QQ does have phone apps, but QQ didn't have this casual business-use to the extent WeChat does today.