Hiring new salespeople can be the most important decision a sales executive makes on a routine basis. Effects of a bad decision can include lost sales, wrecked customer relationships and the heavy cost of replacing a rep who’s below par. Even average hiring decisions leave money on the table – the money your firm could make by hiring people who have the potential to become top performers.

John Connor couldn’t believe what he had just heard. It had been a long day that had included a four-hour drive along Interstate 37 on a steamy April morning in Texas. Connor, president of Quality Assessments Mystery Shoppers Inc., was meeting with the owner of six fast-food restaurants in Corpus Christi to pitch his firm’s service: sending undercover evaluators to assess employees’ customer service skills. The meeting had gone well so far. The prospect saw the need for third-party assessments and liked that Connor had a track record in food service. Connor had every reason to expect that he’d be able to strike a deal.

“Sales reps are probably the hardest employees to bring into a classroom for two or three days,” says Joselyn Davis, vice president of product development for The Forum Corporation, a Boston-based global training company that designs programs for Fortune 500 companies. Why? Ask any sales manager.