Two weeks after a middling launch on IH/HN/Reddit/PH, I'm sitting pretty at just over 50 recurring users. Looking at analytics, it looks like almost all of 'em came from Hacker News -- which is no real surprise, since almost all the traffic to the https://donel.ist landing page has come from one Show HN and a couple upvoted comments on productivity-related discussions.
Peeking at analytics, it looks like those 50+ users are coming back daily to log new items to their done lists; a few of them have even set up public lists that are getting non-trivial traffic of their own!