THOUGHT: Email as Username Impractical?

With the last few projects built, I have solely used an email address for the username when logging in. With smaller internal projects it doesn't matter how you handle usernames, but it got me thinking about bigger projects. Are you a member of a social network / community that uses actual usernames instead of email addresses? How many of those have names like jeff10, jonny17, etc? I hate having several usernames and trying to remember which is which. Then, if my username is already taken, now I have to come up with a new one. While the idea of OpenID/OAuth is not necessarily to cut down on how many different logins' you have, I think it is effective in that area.

Since only one person/entity can actively own an email address, I like to authenticate users based on that. Now bob can continue to use his bob@aol.com address and not worry if he is "bob" or "bob1974". Using this approach there are 2 downsides:

a. If your email gets hacked and you used the same one for all your websites that's a lot of access the intruder has.

b. In a community your names are generally displayed so you know who you are talking about. If you were to display the email addresses then you are making your users easy targets for spammers (NOT GOOD!). In this type of website you could have display names but run into the problem of having 15 people named Mike. Therefore you would have to make them unique and your back in a situation of having usernames.

After thinking about this topic for a little bit I have concluded that if you are running a community site, it is impractical to use only email addresses, but for internal / non community websites it works out good.

Did this turn out to be a waste of my time? Not entirely. As I continue to do projects requiring authentication, I think I will take into consideration the pros and cons of using email vs. username.

For other developers out there, please do not assign random numbers as the username. There are a few big internet companies doing that and it's a pain. When I need to login to an account with these numbers assigned I always have to refer to an email or go through the "forgot your username" process. STOP IT!!!