Persuasion is a key ability of any successful salespeople.  Think of the worst car salesperson or door-to-door salesperson you have encountered and you will know why this ability is so critical to success.  CNNMoney.com’s article - How persuasive are you? - interviews an individual who runs the Persuasion Institute who brought up this fine point:

Let’s take, for instance, how we handle objections, whether from a customer or some other audience, such as a boss we’re asking for a raise. Early on in life, we learn to perceive objections as opposition, so we get defensive. An unskilled persuader, often without realizing it, will show tension, uneasiness, or irritation when someone raises an objection, usually because the objection or concern stirs up the persuader’s own insecurities: “Aren’t I doing a good enough job explaining this? Didn’t I go over that already?” This way of thinking will only make matters worse.

By contrast, great persuaders who have learned new persuasion skills know how to welcome objections. Instead of seeing them as opposition, these persuaders see objections as a natural, and valuable, part of the process. They use their audience’s concerns as a way to open a dialogue, a chance to exchange ideas and discover new areas of common ground. Truly great persuaders may cut to the chase by addressing an objection before it’s even been voiced, just to get that communications ball rolling.

I say that is a fine point in that how salespeople handle rejection is key to their success.  We often discuss what traits are most important in sales and I think I would vote for handling rejection.  I think it is, in simple terms, the key differentiator between high-performance sales and mediocrity.