This is probably mostly of interest to HubSpotters themselves, but in April 2011, we hit a milestone: more than 1,000 releases of our software.
We had 1,112 releases, to be precise, counting both our QA (or integration) environment and production. That's 1,112 / 21 ~ 53 releases per working day of the month, on average.
Obviously not every release is big nor does each one contain new functionality. Many are bug fixes, small iterations on existing features, usability / UI improvements, and more. And many of these just went to our QA environment, which customers don't see.
But to do this many releases without impacting downtime (we were solidly at 99.99% uptime for the month, easily meeting our SLAs), feels good. Having a "kitchen sink" team dedicated to deploy tools, scripts, monitoring, and the like, just makes everyone more productive and deploys safer.
We're not at continuous deployment yet, but I hope to get there one day.