It depends how you group them. Arguably, SMD is completely different from OWMD. While some hardcore fans go on both, they each attract a completely different 'regular' crowd as people are drawn to their primary alliance. So in that respect, SMD has historically been an annual Do, no different from any of the others you mentioned.

Having said that, it's clearly not that simple. Having Nordic & SMD so close together is definitely having an impact as many 'frequent' participants choose one or the other. OTOH, if we announced a SkyTeamDo, we'd probably see huge pickup even if it was in November, as the pent up demand from Delta flyers would more than make up for some past MD attendees not going on it.

Finding the ideal number of events and the ideal mix of alliances/airlines/sponsors is difficult, but with each event we get better at it. Will we hold back-to-back events again? No, probably not. Can the community support more than one MD per year? Seems like yes. Can it support five? No. Where does the perfect balance lie? Still don't know. Maybe 2 events per year? That could mean a cycle of the 3 alliances and a non-alliance MD once every two years. But does each alliance have the same attraction rate, and are the airlines within each alliance as willing to host? Maybe, maybe not. Many variables to consider.

There are 100s of questions to consider on this and arguably more than one right answer. But we're still getting there.