The curious case of example.com
The case of example.com, example.net and example.org is peculiar.
For example, example.com has a Page Rank of 7 and over 400,000 inbound links. However its content is only these two lines:
Have You Reached this web page by typing “example.com”, “example.net”, or “example.org” into your web browser.
These domain names are Reserved for use in documentation and are not available for registration. See RFC 2606, Section 3.
Those domains are not even indexed on any search engine. In fact, if we look at their robots.txt files, they have prevented the search engine spiders from indexing them using:
In Wikipedia we can see that they are an exception, because they are reserved second-level domains (in RFC 2606, section 3) to be used in examples and for documentation, this means that they can’t be registered.
The IANA (Internet Assigned Numbers Authority) reserved them to allow the writing of explanatory documents that mention a nonexistent domain.