Who is the most successful salesperson on your team? The one with the best product knowledge? Or the greatest sales skills? Or the most in-depth understanding of your customers? If you picked any of these, you were wrong. Rather than guess what drives sales success, learn the right answer from America's best sales force.

In very real ways, talent is key to both hiring and developing employees. But beware: While selection and development processes may be similar, they actually require quite distinct tools.

Sales reps are always seeking the edge -- always trying to find a new way to wow their clients. Gallup has identified four key dimensions and eight questions that will help them do just that.

Gallup's very first studies of sales forces more than four decades ago yielded some conclusions that are as valid now as they were then. One of those conclusions is that managers make a difference. If you want to improve the quality of your sales organization, start by improving the quality of your front-line sales managers.