As a lot of people have already mentioned on this thread, I think that bi-monthly or less will definitely help attendance. The last few nights have seemed to have come around very quickly and I can understand how this might put some off whether the reasons are financial, having time available to attend or worst case thinking 'the 100 Club...AGAIN!'
The anniversary and Christmas events are always well attended and excellent nights - the 30th was outstanding! I think more people make the effort for these as they can plan them and make any travel and accommodation plans they need, and know that there'll be friends and a higher concentration of soulies attending. Perhaps the same thing would happen in a less frequent standard night?
I know the question over the 'general public' has been debated a lot. As long as there's no trouble and anyone drinking on the dance floor is asked/told not to there shouldn't be a problem. I understand that they are helping to fund the club and you hope that some of them actually enjoy the night rather than just using it as a late night drinking hole.
There's nothing wrong with the music policy or DJ line-up in my opinion. Both are spot on!
The 100 Club is a very special place, loved by lots of passionate people. I'm sure it will recover from this temporary blip.
Steve