I started it in April 2014 and it's making about $1,000/month. Haven't invested time into it (busy day job) in the past 2-3 months. I've got a bunch of ideas how to grow it, but time is a serious constraint
I am using the income to help fund my new project http://timeblock.com a resource/time management and project overview system that is made with a makers schedule in mind!
To clarify, I have signed contracts that are committing to certain lengths of time. It's not something that I would have quit my day job for, without a significant part of the risks mitigated.
Started this while living in Hong Kong as a way to bring in coffee from the popular roasters in the USA, and expanded to the states within 8 months. Good times so far, and it's still a side project. Used the profits from the HK side of the business to launch USA side.
I'd be interested to hear how people with profitable side projects went from side project to profitability.