Here's some stories about failed conventions of the past that I've been to, or close to, or heard about.
EX-CON (1986)- local Atlanta area guy went from a failed comic book company to a failed convention. I knew him from the failed comic book company and wanted no part of his convention, which was OK by him, as he was firmly in the driver's seat for this ego trip. He sold memberships, sold dealers tables, invited guests, printed flyers, booked hotel space. The weekend of the convention, the hotel kindly informed him that he wasn't anywhere near making the room block he promised and that unless he paid for the meeting space in advance in cash, his convention wasn't happening. Convention didn't happen, but I understand there were some cool parties in the already-reserved rooms. A friend of mine in high school bought a membership and bugged me constantly about getting a refund. FAILURE: no reason for this con to exist, no reason for anyone to attend. Prime example of convention for the sake of organizer's ego.
OUTWORLD (1996)- Castlegate. This goth-vampire-white wolf games style convention was at first started by a local fan guy who wanted us to run the anime room. His contact information was a telephone number at his job, which was at Waffle House, at which he was no longer employed when I called. The convention actually happened, and we actually did run the anime room, which was sparsely attended. All in all not a total failure- the 300 or so people who showed up seemed to enjoy themselves - but was there any need for this show to exist? Not really. We spent Saturday night shooting darts at each other and annoying the LARPers. FAILURE: not really a failure, but not enough of a success to impel anyone to want to do another one.
STARCON & COMICS (1995)- organizers of Atlanta Fantasy Fair decided to put on a show that was basically Atlanta Fantasy Fair under another name so as to cut one of Atlanta Fantasy Fair's owners from their share of the profits. Sadly, these were the people that were responsible for turning AFF from Atlanta's largest convention into a shell of its former self, and what Atlanta's con-going audience wanted was not a repeat of the failed AFF but what we were doing down the street on the same weekend, which was AWA. FAILURE: spent a lot of money on unattractive guests. Pretended their failed convention model would somehow magically work THIS time.
ATLANTA COMIC-CON (2001-2003) - This Duluth-based convention was started by a guy who ran comic book shops in Roswell and Atlanta. Started off fairly large in the Gwinnett Civic Center and the hotel nearby. Of course they had to have an anime room and they asked us to run it. The anime room was sparsely attended. The convention itself had decent attendance but totally spent way too much money on the convention center, guests, ancillary stuff like T-shirts, etc. Next year the attendance was about the same, if not a little less. Year after that they were in half the space at the convention center, attendance was even less. FAILURE: starting off way too big their first year with a vastly too ambitious program in a vastly too expensive convention center. Too many Hollywood wanna-be players (the guys who directed "Free Enterprise"?), too many people flown in from across the country, not enough badges to pay for it all.
EDITED TO ADD: Seriously, "Atlanta Comic-Con"? That's the name you're going with? Because that's about as painfully generic as you can get without a plain white box and a sans-serif font.
CON NO BAKA: (2005) Much has been written about this 2006 show. An anime/gaming con in a blank spot on the convention calendar, in Anime North's hotel, the hotel management pulled the plug Saturday night when it became obvious that there was no way CNB would be able to pay for Sunday's meeting space. The convention's failure is a classic case of Con Chair Myopia, inability to delegate, hands-on disease, willful blindness, whatever you want to call it. Chair ignored reasonable estimates of attendance and booked much more meeting space than was required, insisted on micro-managing details that should have been left to subordinates, and generally made everyone realize this convention existed so that the con chair could say "I ran a convention". FAILURE: Pretending your 300-person convention is a 1000 person convention will not magically make it a 1000 person convention, and if you actually are going to pretend your convention will get 1000 attendees, don't insist upon doing EVERYTHING yourself, so that when the shit hits the fan you aren't in the con office stapling program books by hand.
JURASSICON (1996?) - I remember seeing advertising for this convention circa 1997-1999 in Atlanta. Did it ever happen?
ATLANTIS -(1994?) I remember seeing advertising for this convention circa 1994-5 in Atlanta. Did it ever happen?
WEAPONSCON was an Atlanta 1987 show started by Atlanta SF fan legend Irv Koch and a like-minded group who felt that the weapons policies of conventions were infringing upon their personal freedoms. Poor babies. At this show, if you arrived without a weapon, they'd pin a paper dagger to your shirt. In practical terms their weapons policy was (a) no automatic weapons -big deal, that's the de facto 'weapons policy' for America, (b) all swords and things had to be peace bonded - again, what most other shows were doing; (c) if you did decide to bring a real firearm you couldn't bring ammunition for it into the show, which highlights the fan community's genius for taking something normal people would consider common sense and enshrining it into law, and (d) you have to listen to an important speech by America's foremost libertarian SF author on why everybody should be able to carry whatever firearms they wanted all the time everywhere, CASE CLOSED!! FAILURE: I wouldn't call this show a 'failure', in that it probably made money and accomplished whatever it was the organizers set out to do, unless it was to convince other conventions to loosen up on their weapons policies, which hasn't happened, and for good reason. Unless you like seeing granny-lady blood spilled on your convention center floor.
ATSUICON (2007) - I wasn't at this show, but reportedly the convention spent way too much, got in way over its head, and on Saturday night held a mass meeting of all the attendees to inform them that the convention was $12,000 in debt and that all 1000 attendees needed to pony up $12 each or the convention would be shut down. The beauty part is that apparently the attendees fell for it. There never was another Atsuicon, which is a very good thing. FAILURE: poor money management skills. Seriously, all their guests were local Texas voice actors or local Texas fan wanna-be guests, their programming was the same old stuff you see at every other anime con, and the cheapest ticket price was $28, $45 at the door. If they did 1000 attendees they had at least $30,000 to play with, not counting selling dealers tables. What the hell did they blow all that money on?
So, what have we learned. Conventions fail for many reasons. Poor money management, ego trips, failure to delegate, insanely optimistic attendance projections, simple bad luck. A complete lack of understanding or purpose lies at the bottom of many of these failed shows - why are you organizing this convention? Why do you expect people to pay money to attend? Is it because it's a convention and has to exist for its own sake? Because that is so not true. History proves it.
There's an existential crisis at the heart of many of these failed shows; they're doing it because they saw others do it and they want the social credit or the respect or the (imaginary) profits they think others are getting from running conventions. What they don't understand is that if you don't love the holy beejeezus out of whatever it is you're starting a convention for, you've ALREADY FAILED. Nothing will repay the time and sweat and blood and tears you'll spend on this project.
There's an organization failure, too. In that you don't need that much organization. Do you really need badges, program books, T-shirts, con suites, video rooms, panels, costume contests, all that nonsense, just because you want to hang out with people who like what you like? Do you have to have a convention for this? Usually you don't. The kids these days are just saying the hell with everything and gathering casually for meetups, photoshoots, World Hetalia Cosplay Daze, you name it, they don't need the convention model to get together. Let the t-shirts and the cosplay chess come when it needs to be there, and not a moment sooner.
In conclusion. We don't need any more fan conventions. We're full up. Host a meetup or a photoshoot or a book club or a picnic or a family reunion instead.