I saw someone on Twitter posing the question:
It struck me as a very interesting question and got me thinking about how large the community actually is! I came up with two data points:
Based on the 2016 Stack Overflow Survey, 5.2% of 46,613 responses (of 56,033 respondents) used Emacs as a development environment. Stack Overflow indicate that they estimated 46 million people visited SO in January alone. If the survey respondents were representative of visitors, that would suggest ~2.0 million users of this sort visited SO in January 2016 (or at least 2,425 users ;-).
In 2015 they asked about preferred text editor. 4.1% of 16,778 resonses (of 26,086 respondents) indicated Emacs or XEmacs. At the time they estimated 32 million people visited SO monthly. These numbers suggest that ~840 thousand users of this sort were visiting SO in February 2015.
They acknowledge both surveys are:
...biased against devs who don't speak English, or who don't like taking English-language surveys.
(and they likely offer a high estimate for their amount of unique traffic)
What other data might shed some light on this question? Maybe the Debian package popularity contest?
