If you take the approach of listening twice as much as you speak, you will be a better communicator. If you become curious and make the conversation about them, be it a customer, friend or family; you will have more influence! 

When people see that you are taking a genuine interest in them, they feel valued and respected. This makes them open up. This gives you a deeper understanding of what they are going through. You are then able to communicate about things they relate to because it is about them. 

This makes you a better communicator, salesman, influencer!