A product line is a group of related products manufactured by a single company, often sharing similar functionalities, targeted at specific demographic groups, or marketed together.
Brands have multiple product lines to target diverse markets, maximize profit potential, and diversify risks.
For example, Apple's product lines include- iPhones, iPads, and Macs.
Line filling and line stretching are the two ways to expand a product line.
When Apple launches a new iPhone, it is part of line filling, which involves adding more items to the existing product line.
Brands will introduce products that enhance profitability and eliminate those that don't contribute to profits to stay competitive.
Conversely, line stretching strategies involve adding new product lines, both upward and downward, to address market gaps and competition.
For instance, BMW introduced the Mini Cooper and Compact 1-Series, representing downward stretching that catered to budget-conscious consumers and expanded market reach.
It launched Rolls Royce for the premium segment, representing upward stretching, which targeted affluent customers and elevated prestige and profit margins.