When you’re talking about your site and won’t mention the real URL, please use example.com. Or example.net. Or example.org. Do not use:
mysite.com
mycompany.com
myclient.com
site1.com
site2.com
primarydomain.com
secondarydomain.com
anything.com
invalid.com
nosuchsite.com
or anything else along these line: they are all taken. The “example” domains are the only ones set aside specifically (RFC 2606, for you geeks) for testing purposes. Thanks for listening.