Have you ever watched a sporting event live or on television and seen the impact of confidence? A team of lower skill can defeat a team of greater skill if its confidence is significantly higher.
Confidence is even more critical in sales. The sales professionals who have the most confidence will often walk out the winners in a competitive bidding situation, even if their price is higher or their product is not superior.
The opposite is also true. They may have the best product in the world, but if they approach their prospects with low confidence, the sale may die.