I'm developing a registration system for a project I'm working on.
Since users tend not to sign up if the process is too long, I've thought to require (at least initially) just their email, where I would send them their automatically generated password (and that would also allow me to verify their email address). That would also prevent them from choosing a weak password in order to complete the registration fast.
I haven't found any downsides so far, but I'm afraid there are some as I've never seen a site using this system.
Is that a good idea?
PS: of course I'm also implementing sign up via Facebook and other similar services to allow people to sign up fast without the need of a password, but many may want to choose the classic sign up for privacy concerns or because they don't use any of those services.