Read section 2 of RFC2606, which describes the purpose of reserving domain names and reserves a few TLDs. Section 3 describes "example.com" and others as "also" reserved to be "used as examples". That means that they should be treated like the top-level domain ".example." and are intended for use in documentation. There is no reason that a documentation placeholder domain should even resolve.
In fact, I recall some controversy when the .COM registrar put up a page on example.com, complete with ads, during one of the Internet bubbles.