Tom Croom's story begins with a moment that's almost too on-the-nose, like it was pulled out of the first draft of an episode of Freaks and Geeks or Stranger Things. He was a 15-year-old geek, hanging out at a friend's house on a Saturday night, where they played Dungeons & Dragons and watched Star Trek — they always spent their Saturday nights playing D&D in front of the TV, because on Saturday nights, the local network would show a rerun of the original Trek, followed by a new episode of The Next Generation.

During one of the commercial breaks, in between dice rolls, the guys noticed a commercial for something called TrekFest. Obviously, they were interested in meeting some fellow nerds, this being long before the Internet gave geeky kids any sense of community. "We had one guy in our group who was old enough to drive — he owned a Trans Am — and I went out and bought sweatpants and sweatshirts from the local K-mart," Croom remembers. "We cut up them with a first-aid kit and made into them costumes, of the redshirts from Star Trek."

Croom and his friends wound up winning that contest, which came with a grand prize of $20. More importantly, the prize was presented to them by George Takei, who was in West Palm Beach as the convention’s guest of honor. That afternoon, the seeds of what would become a full-time passion were planted.

Today, Croom runs Green Mustard Entertainment, a multi-pronged company specializing in fan conventions and events that operates across North America. Since 2007, Green Mustard has put up its own conventions and programmed other shows; more recently, the company began helping actors and other talent score paydays for attending similar fan-focused gatherings.

This golden age of geek media has sparked an incredible boom in fan conventions, trade shows, meet-ups, and special events. It is both a global industry, with major corporations lugging trailers, toys, and old TV stars across oceans and continents — next week is the annual Moscow Comic-Con — and a patchwork of local passion projects, in which fans pool together resources in celebration of their favorite fantastical pastime. Croom is one of a number of professionals who operate in that middle level, running conventions in mid-sized cities for particular clientele, working to turn a profit in an increasingly crowded field.

Scott Zillner is another member of the fan convention's hustling middle class, running a number of events on the West Coast, primarily focused on toys and Japanese tokusatsu culture. The largest of his conventions, Power Morphicon, brings in 10,000 or more Power Rangers super-fans to Anaheim for each biannual installment. That's a long way from Zillner's first convention experience as a kid in 1980s Sacramento in the early days of fan meet-ups.

"The first show I ever did, I was 14 and I just set up as a vendor," he tells SYFY WIRE. "I literally had my mom drop me off at the convention center, I took out my boxes of comics and toys, set up at a table and sold them, then packed it all up and called her on a payphone and said, 'Pick me up. I'm done.'"

Exactly 30 years later, Zillner was at the Scottish Rite in Sacramento to throw his own toy show, a nice round number milestone that he recognized only in hindsight. At the time, he was too busy with weekly conventions to acknowledge anniversaries, with his time consumed by putting up booths and running his own large events. He had started out as a toy designer and artist, working on everything from toy painting to set dressing, but tokusatsu toys — which had first captured his attention when he got a toy robot for Christmas back in 1980 — stayed his true calling.

"It never really left me; I'd work a regular job and then on the weekend I would go and do a convention here and there," he remembers. "Originally I wanted to be an artist, but I made more money selling toys than I did drawing superheroes. I made the switch from being an artist at conventions to selling stuff at conventions. At a certain point it just became more of an everyday thing."

Croom's journey from accepting a cosplay prize from Mr. Sulu to running his own conventions was hardly a direct line. He worked in a variety of jobs, including as a boat operator for the Jaws ride at Universal Studios. That's where he met his future wife, whose appreciation of Sailor Moon kickstarted his interest in anime (he admits that learning about the art form wasn't exactly his original goal). A decade after that initial Trek Con, they stumbled upon another convention — this time, his girlfriend won the costume contest.

A year later, Croom found himself in charge of that convention — the founder had suffered a nervous breakdown — and after that, he launched Wasabi Anime Club. At first, it was really just a series of ultra-weird and nerdy shows, offering local Florida geeks stimulating entertainment like Broadway-style musical numbers, '80s dance parties, and eclectic cosplay contests. Word spread, the events grew, and by 2007, he was being invited to organize events at other conventions. Soon after, he took a shot at creating his own full-on convention.

"We tried to create a pure science fiction convention, and I was trying to harken back to the days of TrekCon, cause everybody was doing a cross-pollination of fandoms," he recalls. "But we were trying to make it about one thing, and be damned good at our one thing. When we did that in 2007, we were literally trying to go against the grain."

The event lost $30,000, but Croom had found his calling. He stayed devoted to the idea of narrowly focused conventions, correctly anticipating a major shift in the booming fan events space, and now has an entire roster of conventions tailored to genres and even single properties. He owns and operates Florida Anime Experience and InvaderCON, while advising and programming for events such as Boston Comic-Con, Fan Expo Canada, and Megacon.

The mid-aughts were a heady time for fans who wanted to hang out and sell one another toys. Facebook was still relatively new, and Twitter was a year away, but the Internet was beginning to bring people together in new ways. Just a year earlier, Zillner had thrown his first convention — a Monsters Among Robots show in Van Nuys, Calif. — and began expanding from there, putting together a list of vendors, actors, production staff, and exhibitors who wanted in on the burgeoning market.

"We didn't lose money, but we didn't make money," he says. "That's pretty much how it always works. A lot of people now these days think, 'Oh, I can just make a show and I'm going to make lots of money,' but actually you lose money for years and years and years building the show up."

Fan conventions now constitute a $4 billion-a-year industry, but much like the U.S. economy writ large, its growth has not been evenly distributed. The major conventions are like pop-up cities — San Diego Comic-Con drew over 135,000 people this year alone — and are largely mandatory events for major studios and networks, which dutifully trot out the stars of their upcoming projects for raucous crowds, who camp out overnight in the hallways of the huge convention centers and plazas that surround them.

Beneath those tentpole events is an ever-expanding universe of smaller conventions, which seem to multiply by the weekend, both in the form of broad catch-all gatherings — the kind Croom tried to avoid a full decade ago — and incredibly niche events. The tracking site ConventionScene.com lists 12 conventions alone for this coming Saturday, and that's inevitably an incomplete snapshot of the day's events.

The boom has meant great business for actors and artists who get paid to meet fans at these events — Arrow star Stephen Amell has even started his own personal appearance agency — but also made it nearly impossible to actually turn a profit.

"The cost for convention halls has skyrocketed," Zillner says. "My costs have more than doubled to tripled on some of my conventions from when I used to do them a couple years ago to now, because the demand for convention space is so high."

And while geek culture is more popular than ever, and attendance has only expanded, fans' budgets are largely fixed, leading to smaller outlays at individual conventions. Instead of spending a boatload on toys and memorabilia at one or two conventions, the influx of local events has resulted in smaller and smaller margins for vendors at each show, which in turn limits the fees that organizers can charge for booths.

At times, it's too much of a good thing. The proliferation of events to attend results in a drain on fans — tickets aren't free — and to some degree is leading to a collapse of some of the more considered and curated conventions. To some degree, Zillner suggests the major shows are starving the smaller ones with a bulk approach.

"Wizard World is the king on the block — they do the most shows, and are also a predator convention," he laments. "They go in and open a convention in a town where a town might be doing good with a local show. They'll put that local show out of business. Like in Sacramento, there's a Wizard World show that moved into that territory. The first show was really, really good because they spent a lot of time and money on it to make everybody come in. Now they're charging $50 a day and you walk in and it's no better than a smaller show. You've been fooled."

Zillner has reduced the number of shows he produces, an attempt to pre-emptively avoid failure and better tailor the conventions that still go on. Meanwhile, Croom plays both angles. Green Mustard runs Talent for Cons, its own agency for voiceover and acting talent, helping them procure slots and fees for convention appearances, and programs the anime activities and exhibits and a wide range of events, including tabletop gaming conventions and broader Comic-Con offshoots.

And as for the conventions they do own, InvaderCON is the perfect example of the more narrow-minded event that seems to be the future of the space. It's devoted exclusively to in the animated cult classic Invader Zim and has remarkably become a yearly event — a double boon to Croom, who represents the voice talent for their convention appearances.

For now, business is good enough to get by; Croom is the sole full-time employee of Green Mustard, while Zillner splits his time among conventions, TV production, and toy industry work. He thinks "the golden age of conventions is over," due to the proliferation of both bigger and more amateur events, but still has no plans on changing course.

"I don't want to dig ditches, I never want to do manual labor for a job," he says, laughing. "You just keep with what you love. I love toys, I love the toy industry, I love conventions, and that's what I do."