Did you know you can use your personal email address as if it were an unlimited number of addresses?
Gmail does not recognise “+” or “.” so if you sign up for a newsletter such as “Coffee Snobs” you can subscribe using email@example.com. You can then identity and filter emails from coffeesnobs easily.
Furthermore if you register for a service such as Twitter you can register multiple usernames with the one email address:
firstname.lastname@example.org for twitter.com/bobsmith1990
email@example.com for twitter.com/bobmagic
I hope that helps.