• 40% interact with the Common Lisp (CL) community on Reddit and 32% on IRC. Indeed, in my experience too https://www.reddit.com/r/lisp/ and Freenode #lisp channels have active and supportive CL communities.
• 89% use SBCL. This is not surprising. SBCL has been the most popular Common Lisp implementation for a long time.
• 48% are 32 years old or younger. This is going to help the CL community to stay active for, I believe, at least another 20 years and perhaps even beyond that if the community can attract more programmers to this language. It is a beautiful language that is a joy to program in, so I do wonder why it isn't more popular.
• 31% are from the US. Countries like China, India, Netherlands, Poland, etc. have less than 3% respondents to the survey.
Incidentally, a bunch of us from Freenode IRC are doing a Common Lisp Programming Challenge this month. The objective is to help beginners get started with learning the language while being a part of a community. You don't have to join Freenode IRC to join the challenge. If you are interested in participating in it, please visit https://github.com/spxy/clpc to participate in the challenge.