Wow, so is improvely is run just by you? 30k a month is impressive. I checked out your blog, but have you ever had anyone else working on it or have you always maintained the full stack?
The only downside to working alone is being on-call 24/7/365 for the servers. I have a good alert system that will wake me up if anything goes wrong overnight, though most components of the stack can fail without taking down a site. Lots of load balancing and warm failovers at a second host just in case.