I have seen some people who were working hard and good at their career area, but never get promoted. They were shy and not good at socializing.They just keep a mild relationship with their bosses on work, never built a good personal relationship with them .They looked down up on these people who liked flattery.But every time, when they heard someone others got promoted ,they heart hurt and felt unfair about themselves.But if they got promoted, they didn't know how to manage the group.So, if you want to got promoted, the first important things is that you should be an outgoing person, communication is the essential skill for a manager.An introverted person needs to change himself before ready to be promoted.If it hard to change your personality, just do your best, you should understand that a diligent and capable person is also an important part of a group.You can win other's respect as well.The only thing you can't do is that never give up and doubt yourself.You are one of a kind.