There's a whole host of reasons, here's a handful: - Some sites will attempt to use the first part of your email address as your username. - Foreign domains a

There's a whole host of reasons, here's a handful: - Some sites will attempt to use the first part of your email address as your username. - Foreign domains are difficult to explain to people who don't understand. - People expect you to say a your username at a domain they have heard of. - Anything other than .com is confusing. eg: johnasmith@gmail.com is easier for humans to digest and computers to parse than john@johnsmith.net or john@smith.be or john@smith.me.uk