Suggestions:
Make a list of interested users in the OP. Not necessarily people who WILL be there, but people who say they MIGHT. Interest breeds interest.
Periodically drop into sitechat to advertise yourselves throughout the week. Encourage people to Ego here.
Let people use this thread to set up additional times where they might be interested in additional games. Sat at 630 might not work for everyone all the time, but an indexed location of what's coming up (similar to the queues but less formal) might help jumpstart interest.
I'mma go back to being lazy and noncommital now.