re: They might not know ...
Actually, Mr. Vancil, I was the one, as President of NSS-NT, who asked the Mars Society folks to participate.
You see, I do make an effort to reach out to people in other space organizations. When we did our World Space Week display last fall I not only had NSS-NT and the Moon Society, but also the Mars Society, Dallas Area Rocket Society, Texas Astronomical Society, and even some Solar System Ambassadors. I got these folks involved, because I try to make sure that everyone gets a chance to speak, and because space is big enough that no one group can presume to speak for all aspects (though NSS is probably the closest as far as popularizing space goes).
Now, whether those folks take the opportunity is another matter...