BBC Earth is a brand used by BBC Worldwide since 2009 to market and distribute the BBC's natural history content to countries other than the United Kingdom. BBC Worldwide is the commercial arm of the public service broadcaster. BBC Earth commercially represents the BBC Natural History Unit, the largest wildlife documentary production house in the world. BBC Earth is responsible for the worldwide marketing and distribution of titles such as Frozen Planet, Life, Blue Planet, and Planet Earth. It has generated sales to over 180 countries.