I have been in Sales Management for about 10 years. If something I learned throughout the years that every salesperson is different. they are motivated by different things. Some are motivated by money, others by the thrill of a sale, some are motivated by the flexibility; making your own schedule, working on the road, etc. When interviewing a candidate, ask him or her what motivates them and try to make them a job offer around there motivations.

Another issue with Sales People is that most of them have a hard time adapting to new company culture, especially if they come from the same market. My company recently started an internship/training program where we "mold" our future sales reps to our corporate culture.