Jeremy C. Reed asks that anyone running pkgsrc install and run
pkgsrc/pkgtools/pkgsurvey. This will send (generally anonymous) data to the pkgsrc project on which packages are being used. Repeating this monthly (as though a cron job) would be best.
If you’re still on the ports system, mail Jeremy the output of
pkg_info. He also hinted that the data on the most popular packages could be used for putting together a DVD.