Congrats on shipping. I run a very different kind of monitoring service (alerts when your cron jobs and other scheduled tasks don't run or take too long, see my profile for details). I'm wondering why you don't offer paid plans. In addition to reward for your work, business users really would rather rely on a business and not a hobby. Maybe your target market is hobbyists but you should certainly consider a paid plan early on. Our subscribers are an important voice in our product decisions and doubly so early on.