I asked Tony Cole, sales development expert, to answer a few questions about hiring sales people. He recently launched a webinar appropriately named "How to  Avoid Salespeople Hiring Mistakes."

1. Why is hiring sales people so difficult?
Hiring sale people is not hard. Hiring the right ones is hard. Why? Too
few good sales people. Poor processes in place to separate pretenders from
contenders. Desparation to hire somone. Wrong profile used for the actual
role.

2. Do people tend to hire salespeople that are like them? If they were
successful, why is that a bad thing?

Success is not always duplicatable based on why one person is deemed
successful. You have to look at criteria to succeed currently and then
determine if the successful person doing the hiring achieved success based
on that criteria or did they get lucky or have an unfair advantage.

3. Are there ways to predict whether a salesperson will perform without
interviewing them?
Certainly a pre hire assesment will help. But it is not a substitute for
all the other steps required in an effective hiring process.