Over the last 30 years about 99% of my work has been exclusively for comics. Maybe even 99.9%. I haven't kept count. However, sometimes I'll be contacted by companies outside of comics to do commercial illustrations for them. Often, it makes a refreshing change, especially when it's for a good client. (And every artist has horror stories about the bad clients, but I don't use my blog for muckraking.) It can be a rewarding experience and it's an area I'd like to venture into more often really. (As long as I can keep doing comics as well of course.)
One pleasurable job recently was doing a few illustrations for Meello, the crowdsourcing company for the built environment. There's the builder 'John' on this blog, and you can see him in context at the Meello website:
Perhaps I'll show some of my other non-comics work here sometime if enough people are interested?