Some services have you pick a username, which is great if you do not want others to know your email address or if you want to use a special nickname. But it can be difficult to remember the username for a service you rarely use, and it can be frustrating to find a unique username on a popular site.
Other services assign you a username, which is easy for the programmers to do. Other services use your email address, but then require extra programming to accommodate the possibility of an email address changing without wrecking other things tied to the account.
So programmers, when you write an application that requires login, what do you use as the username?
What do you use for usernames?
(Thanks to longtime reader and friend Mathew O’Hare for suggesting this question.)