Last Wednesday night, about 50 girls huddled in front of Madison Square Garden, warmed only by North Face jackets and their burning love for Justin Bieber. They were Beliebers, and for the next couple hours I planned to tag along as they rampaged through New York. Here are the crazy results.

But, man, is it uncomfortable to have fifty chattering girls, average age 15(ish), suddenly fall silent and turn to stare at you as one. This happened when I walked up to introduce myself—like something out of Children of the Corn! There were a few moms there, and when I started snapping pictures one asked me, suspiciously, "Who do you write for, again?" I told her, hoping she didn't have a smartphone with which she could discover that my most-read post ever is a blurry picture of Anthony Weiner's penis.

The Beliebers had gathered that night for a buyout, a unique form of Justin Bieber fandom and one of the reasons why he consistently posts huge CD sales despite the fact the majority of his fanbase came out of the womb with iPod earbuds on. In a buyout, Beliebers descend in a biblical swarm on a store that sells Justin Bieber CDs. They buy out the entire stock, two or three copies per girl if they've got the cash. Of course these die-hards already have all of Justin's music, so the CDs are donated to charity after the buyout, usually a local children's hospital. Buyouts are happening all over the country now, to celebrate the release of Justin's new Christmas album, Under the Mistletoe.

At about 8:00pm a pair of older girls mounted a wall in front of the tittering crowd, shouting like generals marshaling an army. This isn't really a metaphor: The buyout was organized via Twitter and Facebook by a Justin Bieber fan group called BieberArmy, which consists of four longtime fans with a popular Bieber fansite and 340,000 Twitter followers. Stephanie, a 19-year-old BieberArmy leader shouted out two ground rules for the evening: 1) Buy as many Justin Bieber CDs as possible and 2) "don't freak out" if Justin Bieber showed up. "Just don't attack him," she stressed.

***

I'll admit a large part of why I was there was the possibility of Justin Bieber showing up and getting attacked. Every buyout is also a summoning ritual, held with the not-very-hidden hope that Justin will materialize after a sufficient number of transactions have been completed. And sometimes he does! Justin stopped by the buyout BieberArmy had organized in August of 2010. Other times lesser members of the Bieber crew are dispatched to buyouts, like his backup dancers and "official DJ." When I asked Stephanie if Justin would actually show up, she replied, "There's a chance."

I thought there was more than a chance. Why else had the buyout been scheduled for the day Justin would be performing at the tree-lighting ceremony in Rockefeller Center? My other hidden agenda was to see to what extent the buyouts were a brilliant marketing campaign by Justin's management. The whole concept seemed a bit too attuned to boosting CD sales. On the Facebook event pages for buyouts throughout the country, I started noticing certain repeated phrases that suggested coordination on a grander scale.

Justin's people are experts at mobilizing their hyperconnected fan base. Scooter Braun, Justin's manager, was caught on the group video chat service Tiny Chat last year urging a bunch of girls to lure their boyfriends into Justin's movie, Never Say Never, with the promise of "makeout sessions." Scooter's Twitter account is constantly filled with shout outs to fans, and, if these fans are to be believed, he's diligent about direct messaging with them with encouragement, or to bat down rumors flying around the Biebersphere.

In fact the BieberArmy girls said it was Scooter who prompted the first buyout. The then-burgeoning group met him at a meet-and-greet in 2009, where he suggested that they organize an Apple-style campout outside record stores in advance of the release of Justin's first album, My World.

"I said, little girls can't do that," Stephanie told me over the phone a few days before the "Under the Mistletoe" buyout. "Let's do something else and get together and buy all the CDs." That December, BieberArmy organized the world's first buyout in 2009 in New York, with about 25 girls. A meme was born.

***

After a few chants, recorded for YouTube, the girls were off in a pack for a nearby Kmart. They were scary fast. The older organizers tried to keep the mob together, one up front, one tailing and a couple on the sides.

The mob was a mobile middle school hallway. A girl on the phone:

Fine, go to Huntington and meet up with your friends! You really don't think of anyone but yourself, do you?
 Hang up on him Carissa!

Many of the girls were excitedly chatting about the possibility of meeting Justin:

When are we leaving?
 We're leaving when I meet him. You know what will happen if we leave. We leave and then he'll come.

The BieberArmy girls led chants of, "When I say JUSTIN you say BIEBER." Pedestrians gaped. Had the Occupy Wall Street protests taken a decidedly strange turn? Grown men seemed particularly put off, shouting things they would never think of saying to a single 13-year-old girl. "Move, you fat bitch!" said one enormous middle aged man as he struggled upstream against the Lilliputian mob.

They streamed down two sets of escalators at the Kmart, into the back corner to the music section then surged forward into the tiny CD aisle. But there were no Justin Bieber CDs. The mob paused, pulsed, and for a second I thought there might be a repeat of the infamous Long Island Belieber Riot of 2009. "Shame on you!" A tiny girl in a grey hoodie shouted at a dumbstruck clerk as they streamed back up the escalators, headed to the Best Buy on 23rd Street and Sixth Avenue.

The Best Buy was where they bought their CDs. Sales Associates quickly went from stunned to selling mode, picking through the crowd with huge stacks of CDs. While waiting for all the girls to make their purchases, more-enterprising fans were making connections: exchanging twitter handles, promoting their own pet Bieber projects. One girl had a charity Twitter account where she donated 10 cents to Stopbullying.org for each follower. Another sold a couple $5 handmade bracelets fashioned from soda can pop tops—also for charity.

These girls were motivated out of pure love of Justin, and wanting to do good. But I bet on some level they understood the mechanisms of attention that underpin Bieber fandom—an intricate hierarchy built on Twitter follower counts and trending hastags. You support Justin in a way that hooks other girls on Twitter and gets more followers. Eventually you build a following to the extent you can launch a Twitter campaign to get Justin to tweet at you or—hope-against-hope—direct message you.

With their buyouts, the BieberArmy girls have perfected the game and are rewarded with backstage passes and a seemingly direct line to Bieber's people. One of the BieberArmy girls has met Justin 10 times.

"We used to be cornier," Stephanie told me. They would wear his merchandise and scream. "Now we try to impress him."

***

Things got weird outside after the buying was done. The organizers suddenly halted the mob outside a cafe half a block away. One organizer named Cher revealed that they'd heard some girls hadn't given up the CDs they bought for charity: "If everyone doesn't put their CDs in the bag, Justin's not coming," she warned, holding a giant trash bag full of most of the girls' CDs.

"This is a buyout, not a meet and greet," explained another organizer. "If this was for you to meet Justin I would have labeled it a meet and greet."

"There are people in a hospital right now who can't afford this because of their surgery!" said Cher.

After a minute of awkward silence, three or four girls emerged from the back of the crowd and sheepishly dropped their CDs into a big bag to be donated to the Children's Hospital of Philadelphia.

While Cher was shaking down the Beliebers, the other organizers had peeled off and were huddled by themselves. One older girl was leaning against the wall smoking a cigarette. Steph was talking into her cell phone: "We just left Best Buy. If they have a flight to catch, tell them not to worry about it." She was talking to Scooter Braun, Justin's manager. Justin wasn't coming.

The sad news was broken to the rest of the girls at the McDonald's where they gathered to shoot some final videos for Justin, and to take pictures of their massive CD haul. "I didn't come to meet him, but my mom wants me to come home," a girl had asked nervously. "Is he going to come?"

That night, the BieberArmy posted a picture to their Twitter, along with the caption, "This is for everyone who made the buyout tonight!" It was a screenshot of one of the girls' iPhones with a Twitter direct message from Justin: "love u guys."