[Gryphin]

Hadrian Aventine
A convention would break even and probalby turn a small profit. The key is to start small and build it each year as you gain experiance.
This worked for BattleGroupe Boston, (the miniatures wargame club I belonged to), and their convention "Havoc".
SG and MM, and other SG game companines will profit indirectly from exposure.
Cons are a lot of work. They can be very rewarding. They can also be a major financial risk if you guarantee a hotel X amount of rooms and they don't get filled.
I have a lot more thoughts if anybody would like them.