I'm wondering about best practices for user registration. I'm leaning towards storing site registrations in a separate registrations table and then once the signup has been confirmed by email transferring the data over to the users table.
The benefit to this would be that reads from the users table are not cluttered with never activated registrations. Another benefit is that the email (username) field can remain unique in the users table but if you attempt to register with an email address that you don't own, the owner of that email address will still be able to register with it as the email field will not be unique in the registrations table.
I'm wondering if this is a common practice or if there's any reason this is not a good idea?