How Do You Manage a Virtual Sales Team to Drive Results?

The Situation
Harry has been managing sales teams for the last ten years. However, all of these sales teams worked out of the corporate offices where he was also located. Because of their locale, he always had visibility into their activities because he could see them.
Now, Harry has just accepted a position with a firm where the entire sales team works out of home offices. During one of the interviews, the CEO shared with Harry that the sales team fails to meet revenue goals. The CEO also has a perception that the team isn’t working very hard. The burden is now on Harry to turn this situation around, but he has never managed a virtual sales team?
Your Challenge
What are your recommendations for Harry to effectively manage his virtual sales team? What are the best practices when managing a virtual sales team?