I believe that a smile is the attribute of a positive attitude, both for yourself and the perception of others.
Attitude, humor and action (persistence) will whip fears and rejection. Fear of failure doesn't exist, if you believe it doesn't.
Customers will want to talk to you if they believe you can solve their problems.
If you believe in your company. If you believe in your product. If you believe in yourself. Then you can march to success.