I’m a big fan of the book by this title from Marshall Goldsmith, and even bigger fan of how well the title applies to the role of a first level sales team leader. Research by Chally has found that up to 85% of top performing sales reps who are promoted to sales leader roles ultimately fail. Part of the reason is that the knowledge and skills that make a sales rep a perennial top performer can actually work against them as a team leader.
Another issue is personal development. Most first level sales leaders (or even those higher up) have never been given the tools and training to be able to effectively coach their team and work with sales reps who most likely have different communication preferences, styles, and levels of process acumen and discipline. We see many sales leaders who want to apply their way of selling uniformly to their team, and one size does not fit all.
When we begin working with a client, we usually find that 90%+ of their prior investments in sales training and tools has been focused on the sales reps, with the remainder focused on how to coach to a specific sales process or method. Very few companies have invested in coaching and leadership development for their frontline sales leaders. The Gallup organization captured this well: “Unless your company is continuously improving the quality of its front-line managers, it's unlikely that you're improving the quality of your sales organization."