Many people have gone broke promoting seminars and events. It’s a gamble.  But let me say this: A 1% response to direct mail is really good, probably more like 1/2% So if it cost you $300 for the room, and $200 in misc expenses, you could spend $1500 on mailings, which after printing and postage of about .50 each, gives you about 3,000 pieces. at one percent it’s 30 people, at .5% it’s 15.  Not counting your time, you can see how the costs add up quickly.