They have ranked the top 500 most popular websites in the world based on Domain Authority, a link-based metric that models how Google ranks websites. Each site is listed by the number of other websites that link to them, along with a Domain Authority score. Let’s have a look at the domains of the businesses on the list. Keep in mind some appear more than once, when the same company owns more than one domain name – see YouTube.com and YouTu.be for example, or google.com and maps.google.com. Global businesses usually have a serious domain name strategy in place to extract the maximum value from their brands.
number of companies
Here is a chart, you can see over 61% of the companies in the top 500 have a .com extension, followed by .org, .edu and .jp. The category “others” consists of domain extension like .eu, .info and others that have a very low (2 or less) representation.