Short for "company" CO is memorable and already recognizable worldwide. This domain is usually used to mean a company or commercial content on the website. Many famous brands, such as Apple, Coca-Cola, Amazon, Disney, VISA, BMW, American Express, have registered their domains in the .CO zone.
Because it’s a similarity to .com, many businesses choose .co as a replacement for .com, when .com is already taken.
The .CO zone is also the national domain of Colombia and is suitable for sites whose subject and content is directly related to this country.