It would use both shared accounts, and auto registration, which depend on how complex the registration system is and what requirements it has. For example, on s

It would use both shared accounts, and auto registration, which depend on how complex the registration system is and what requirements it has. For example, on sites which have lots of traffic it is preferable to have a swarm of newly registered accounts arriving all the time because of unreliable users of the account deleting it, changing the password etc. On less traffic'd sites it would be preferable to have a few small accounts. I've observed this on bugmenot...