I hate to necro this thread, but it popped up in my Google search. IMHO you're doing yourself a disservice by not putting Combat Mission on Steam. They have and continue to impact gaming in a very significant and positive way, in part due to their stellar service and dedicated community.
This game series should not be such a well kept secret Their ability to promote through advertising and word of mouth on the forums makes it seem like a no-brainer. Black Sea is coming soon and I think a lot of people would be intrigued by it's premise and gameplay mechanics.
Combat Mission is what strategy enthusiasts want and it would be a shame if they never got to play it simply because they didn't know where to look. Just because it is on Steam doesn't mean you have to stop your own distribution. The older grogs can still play with the website community, without being interfered with.
I'm a Steam fan because of automatic updates, messaging, the forums, community groups, mod uploads on the Workshop, ect. Steam is popular for a reason- it works. Please consider it