Resume and interviewing skills aren't enough when it comes to figuring out whether a job candidate would make a great salesperson. Over the years, I've found that money motivation is the factor that sets apart great salespeople from the mediocre ones, or worse.
Money motivation means a salesperson lives to earn commissions and win prizes. A really money-motivated salesperson does what it takes to close the sale. To accomplish this, such salespeople become masters of strategy. They know the product, they know the competition, and they have good relationships with their customers.
It's crucial that a business owner or his or her sales department manager figures out whether a job candidate has this, because money motivation isn't a skill. It's a trait. A sales manager can add focus to a salesperson's desire to make money, but the manager can't force the salesperson to become money motivated.
I've seen companies too often focus on other factors that are less important. Expect disappointment if you're basing your hiring decision on past performance. The world is full of salespeople who caught a lucky break and were in the right place at the right time for a hot product.