Examples of category killers include Wal-Mart, Best Buy and Amazon. A category killer is a company, service or brand that has such a unique advantage that it is extremely difficult for competitors to operate profitably.
Wal-Mart is thought of a category killer because it has caused many smaller businesses to go out of business. With its massive supply chain, Wal-Mart's prices are too low for many smaller businesses to match.
Amazon is viewed as a category killer for music and book stores. And eBay holds 90 percent of the person-to-person consumer auction market, meaning eBay has very little competition.
Big-box stores are often considered category killers. For instance, Best Buy's dominance of the consumer electronics market left many smaller stores unable to compete. When a Home Depot or Loews opens up, small, local hardware stores often close. Similarly, Staples and Office Depot dominate the market for office supplies.
Category killers tend to wipe out nearly all other competitors in a market. As a result, the market share of the category killer increases. Category killers attain their status through use of one or more competitive advantages, including efficient distribution, heavy buying power and the ability to deliver wide variety and low prices.