5 reasons not to use email for login

Using email for login seems a compelling choice, because an email address is guaranteed to be globally unique—no two people will have the same email. Unfortunately, there are some problems.

h2. 1. People have more than one email

People often have several different emails, and they can’t remember which one they used. Some of us have our own domain and use the firstname@lastname.com format always, but a lot of people have an email address from they employer, one from Hotmail, and a Gmail one, and they forget which one they used for your site. The next time they come back, they try to log in with the wrong one, think that they must not have an account, and register for another one.

h2. 2. People use fake emails

People are afraid of spam, and so they’ll tend to use fake emails, or mailinator.com emails, or something else that they’ll forget the next time they come back. Even people with their own domain may use nospam@lastname.com or yourservice@lastname.com or some other variation to avoid the risk of getting spam to their primary address. Again, they’ll end up registering a new account.

h2. 3. People change emails

Some people use an email address that belong to their employer and then change jobs. Or they have a hotmail account and it expires because they don’t use it often. For whatever reason, they may loose access to the mailbox. Now their account is associated with an email they no longer use, and they’re likely to forget that.

h2. 4. A username imposes fewer constraints

When you ask for email, there’s the constraint that it should be a working email, and it needs to follow a certain format. With usernames, people can choose freely, so long as other people haven’t used the same username. People will frequently have a username that they typically use, which can be their own name (lowercased and with dot instead of space, perhaps), or it can be a nickname that they often use.

h2. 5. A username lets people express themselves

With an inventive nickname, people get to express a bit of their personality in their username, if they so choose. It’s not necessarily something others get to see, but it can still give that warm fuzzy feeling. (and perhaps a bit more commitment in the long term?)

You’d think, that by asking for both username and email you’ll be asking for two things instead of one, but in practice, you’re better off going with username, and use email for backup.