This isn't really a brainwave on how to promote cat sailing, more an observation on human behaviour.
I've noticed that when a hard core group of club sailors regularly race a particular class of boat, other club sailors will change to that boat type, and new incoming members will look to obtain the boat that they see racing regularly. In my local club a few years ago there was a strong fleet of Nacra 6.0's. After a couple of years they all disappeared pretty much at the same time. I am now the only member sailing a cat. Everyone else sails monohulls - mostly Lasers (see predominant class emerging!!). The next sailing club along the coast is now predominantly cat sailors (mostly Dart 18's), new members to this club are looking to get this cat type as are longer established members. I've no idea on how to promote the catamaran, its the speed thing that does it for me!

Chris