For this to work as promotion to new members, I think it'd have to be very attractive, enough for someone to use it although they don't know what it's about when they first see it. Would you use a "John's Garage" persona? No, you don't know them, don't care about them. The only thing that'd make you pick it is if you like how it looks. Heck, if it's ugly, not even supporters will use it. So for this approach to work, it has to be pretty and popular. IMHO.