To me, its not just about lazy registration. It's about the mindset of the user when you ask them to do something.
For example, when they have created some content and want to save it, that is the time to ask for email/password. It works better because of the implication: you are saving their work.
For example, when they have created some content and want to save it, that is the time to ask for email/password. It works better because of the implication: you are saving their work.