They can look at other people's comments and in that way see how the platform works, without typing their email. Like here at HN, you can look at this topic and

They can look at other people's comments and in that way see how the platform works, without typing their email. Like here at HN, you can look at this topic and read other people's comments, also before you've created an account (typed your email) yourself. ... Aha, now I see you've added a demo :- )