We wanted to be very conservative about our spamminess and decided to send one single email with explicit opt-in for more. We had links like this: * I'm a

We wanted to be very conservative about our spamminess and decided to send one single email with explicit opt-in for more. We had links like this: * I'm a Beeminder groupie (email me daily if you want) * Keep me in the loop (email at most weekly) * Don't let me forget about you (at most monthly) * Tell me if you cure cancer or something (at most yearly) 13% of users clicked one of those (2% chose "yearly" with about 4% each for daily/weekly/monthly). I'm thinking we should instead force a choice at sign-up.