I am tempted to put my telemarketing experience to use and see if I can get us a feature in some magazine or other... The only thing about this being I would want to talk to a senior member of sindome first to be sure I don't misrepresent them and that they are cool with me doing that on their behalf. Aside from that social media and friends seems to be the way to go.
Aside from TMC and TMS, you might also consider the in-game message boards on other related game types. MUSH, MUX, and Rhost codebases are all very similar and require role-playing. The folks there will undestand the idea behind the game, and most such games do have message boards to be used for elseMU advertising.
Wanted to post more, but I had to use my iPad and it takes me forever to type on this thing. :)