The impact of how product line breadth affects a salesperson is unclear in the existing literature. While numerous product lines can provide certain benefits to the salesperson, they may also have a dark side. This research examines the impact of number product lines handled by the salespeople on their performance, role stress, and job satisfaction. Based on role and schema theories, we test a series of curvilinear and conditional effects, using data collected from salespeople across multiple industries. Our analysis indicates non-linear relationships between number of product lines handled by the salesperson and salesperson performance and role stress. Further, these relationships are contingent on the complexity of products, complementarity of product lines, and lines acquired through mergers and acquisitions. These results show the complex effects of product lines on the salesperson and recognize both the benefits and drawbacks of product line breadth.