Complementary products

Complementary products are goods or services bought to be used together, so sales of one often lead to sales of the other. Market research helps an entrepreneur understand how their own good or service complements others on the market: what customers buy alongside a product like theirs, and whether they could offer it too or work with a business that already does. A complement is not a competitor. A competitor does the same job and is bought instead, while a complement is bought as well.

A good or service fits with another when each makes the other more useful. An entrepreneur planning to sell refillable water bottles could research what people buy to use with a bottle. Findings might show customers also buy cleaning brushes, carry straps and flavoured water tablets. None of these does the bottle's job, so none competes with it, but each makes it more useful. The entrepreneur could sell a brush with every bottle or add accessories to the range, so every bottle sold becomes a chance to sell something extra.

Complementary or competing?

Research into complements can change a decision. If the findings show that most customers already own a brush, the entrepreneur might stock straps instead, or team up with a local business that sells tablets so both products are promoted together. Carrying out this research before launch lowers the risk of missing an easy chance to sell more to the same customer.