The numbers
How this whole thing is going, in public. One referral opens it.
Everything on hn.today is free. This page is the exception, and only just: it opens the moment you bring one other reader to the daily email.
You'll see how many subscribers there are and how that has moved, which stories readers actually clicked against which ones Hacker News upvoted, where the clicks land by category, and who has referred the most readers.