Because there are additional features coming soon: following users - and notifying a person they are being followed, subscribing to topics/websites/etc. Follow

Because there are additional features coming soon: following users - and notifying a person they are being followed, subscribing to topics/websites/etc. Following a user and them being notified requires a hacker news username to be verified, so we aren't sending out 40 emails that "tw1010 is being followed by jermaustin1" when the only person who cares would be the real tw1010.