A common mistake for new managers is to do their reps' jobs for them, especially in tough deals. This approach, born from insecurity or a desire to prove worth, prevents the team from developing self-sufficiency and ultimately fails to scale. The manager's true job is to build skills and muscle in their reps.

A leader's role in a sales call is to empower the rep, not to perform. When a manager takes over a meeting, they disempower their rep and effectively take ownership of the account. MongoDB's CRO Cedric Pech calls this 'promoting yourself into being the rep,' a mistake that stunts rep development and creates customer confusion.

Promoting top individual contributors into management often backfires. Their competitive nature, which drove individual success, makes it hard to share tips, empathize with struggling team members, or handle interpersonal issues, turning a perceived win-win into a lose-lose situation.

Sales leaders must identify reps who focus all their energy on one large, one-time deal, neglecting future pipeline. This "flash in the pan" behavior leads to inconsistent performance. The solution is coaching consistent, daily activities that sustain long-term success.

First-time managers, often former top performers, default to doing the work for their reps. This creates dependency and prevents the team from developing self-sufficiency, which is crucial for scaling. A manager's true role is to build the team's skills, even if it's slower in the short term.

Significant performance issues are rarely caused by a single event. Instead, they result from a slow, gradual erosion of standards, or "drifting." This manifests as coaching becoming optional, inspections ceasing, and managers habitually rescuing deals, leading to long-term decline.

High-performing salespeople promoted to leadership can get bored. To get their adrenaline fix, they'll stir the pot by frequently changing strategies or creating unnecessary drama, which destabilizes their teams and undermines long-term success.

A leader who constantly shields their team from hardship and 'does the hunting' can become a superhero. While well-intentioned, this behavior removes the team's need to be hungry and resourceful, fostering a culture of entitlement instead of high performance.

Leaders often tolerate a top salesperson who is toxic because they drive short-term revenue. This is a fatal mistake. Tolerating this "cultural cancer" for immediate economic gain will destroy morale, increase turnover, and ultimately undermine the business's long-term health.