The problems with a poll is that Solo players dont tend to create a login, and rarely stop by unless they are looking for something. But creating a login and visiting regularly is almost a requirement for MultiPlay. So asking in this forum tends to skew the numbers. Dom3 has sold many many more copies than the number of players here yet many of those are just as continual in their playing.
The active Solo players here tend to be the people involved in creating some of the most popular addons. Maps, mods, 3rd party programs, informational databases and spreadsheets. Those people create accounts here to make their works available and track threads discussing those works.
My website caters to everyone, and one of the few that carries items for solo play. I see quite abit of soloer traffic there.
www.Dom3Minions.com
My site also caters to many different Dom3 groups from many different forums. I agree that CBM is quite popular here (about 50%) but not so much on other forums. And as you said ver 1.6 is quite popular with some groups more than 1.8