For sales managers, this is not an easy question to answer. The number of salespeople affects profitably by impacting both revenues and costs. It’s easy to estimate costs by looking at historical compensation, benefits, field support, and travel costs per salesperson. But it’s much more difficult to predict revenues, as it requires understanding how complexities such as customer needs, the economy, and the effectiveness of your and your competitor’s salespeople, influence a sales force’s ability to generate sales.