The negative impact of a company's new product on the sales performance of its existing related products. Market cannibalization refers to a situation where a new product "eats" up the sales and demand of an existing product. This can negatively affect both the sales volume and market share of the existing product. Market cannibalization occurs when a new product intrudes on the existing market for the older product, rather than expanding the company's market base. Rather than appealing to a new segment of the market and increasing market share, the new product appeals to the company's current market, resulting in reduced sales and market share for the existing product.