During the first two months, I personally emailed every person who signed up for our newsletter to find out what kinds of people are interested in our service. It was great! A lot of interesting conversations evolved from very short emails with the subject "One quick question".
Here's why I'm really mad at myself, right now
In October, we set up a waitlist for people who want to sign up for SHNUPS. And, I don't know why, we stopped emailing people. It's crazy, because signing up for a waitlist is bigger of a commitment than for a weekly newsletter. We could've found out so much about our audience, but we thought we'd rather spend more time on developing the functionality to invite them as soon as possible. Big mistake!
Yesterday, we did some research and learned that a lot of people working at communications agencies (our target sales partners) signed up. We emailed them, but chances are high that they can't remember services they signed up for months ago (happened to me).
How do you learn from your users? Keen on hearing some stories!