A product line refers to a group of related products sold by the same company under a single brand. Companies create a product line to leverage brand loyalty and meet a spectrum of customer needs.

• Product line decisions, including line filling and line stretching, are significant strategies brands utilize to optimize market reach and profitability.
• Line filling entails introducing more items within the existing range of a product line to compete more comprehensively in the industry. This strategy is often used to target every possible niche in a market, limiting space for competitors and catering to diverse customer needs.
• Conversely, line stretching involves extending a company's product line beyond its current range, either upwards to cater to a more premium segment or downwards to accommodate a lower-end market. The objective is to reach new customers, defend the existing market, or create a growth path. Stretch perceptions can significantly influence consumer responses to brand line stretches, affecting their perceived value and purchase decisions.
• These strategies are vital as they help businesses differentiate their offerings, meet varying consumer demands, and gain a competitive advantage.