Reasons why prospects don't buy

Research shows it takes seven contacts within 18 months to win a new sale. But, when the phone calls have been made, the faxes sent and the sales letters mailed, what are the reasons prospects don't buy?

Some of the reasons are:
1. The prospect has no need right now
2. The prospect is happy with their current supplier
 
OR, for one of the following reasons:

Because the sales person is:
=> Not asking the right questions
=> Not listening to the prospect
=> Interrupting the prospect
=> Not showing empathy for a problem
=> Trying to sell features and not benefits
=> Not communicating the value offered
=> Not asking for the order