Heres what Practicalsteve from pinside had to say as I started a thread there as these guys are experienced in enjoying and running these type of shows.

"The best shows I have been to have these elements:

1. Either just pinball or pinball mixed with arcade, I like both, really just depends what you can get in there. Lots of shows offer free admission if collectors bring in one of their own machines to play.

2. Tournaments, can be laid back and casual or as in depth and long as you want to make them.

3. Vendors or a swap meet flea market- lots of shows have either a flea market in the parking lot were people can sell old machines, or parts vendors inside, I usually pick up a lot of parts at shows.

4. raffles or giveaways- you may be able to get some of the big names like stern to offer a prize you can raffle off for free publicity. some shows will have old or even new machines they raffle off, you just make the ticket x amount of dollars and sell only as many tickets as needed to make up the cost of the machine, most shows that have this sell out of all the tickets quickly and the cost is made up.

5. guest speakers or how to clinics or a history lesson. If you could get someone big in the pinball world to give a talk that would be great. Anyone that knows a lot about repairs could give a how to clinic, or if you have someone who is knowledgable they could give a walkthough and give a history of the machines.

As far as forum conflict I have never experienced that.

You could hold it at a hotel convention center, some kind of show hall, any place you could rent with a lot of power for all those pins."