I have been running one for almost 6 years now. It is very active and has little support from Mercury. We meet once each quarter and I always have at least one and usually two guest speakers.
It just takes persistance.
Success is the ability to go from one failure to another with no loss of enthusiasm.
~ Winston Churchill ~
I strted it and yes it is affiliated with Mercury. They do very little except supply door prizes and teaching support from time to time. I have to find my own speakers, but that really isn't hard if you like networking. Contact your regional sales manager and tell him/her that you want to start a local user group.
Two my biggest challenges were:
1) Finding a room for these meetings. Possible options are: a sponsor or a free room in a library or in a community centre.
2) Finding all Mercury users in your area. Cooperation with Mercury might be extremely beneficial.