"Our Santa suits have always sold to the Santa who dresses up at the mall or dad dressing up at home," said Melissa Sprich, Party City's vice president of costumes and accessories. "But we started to see an increase in sales and were hearing that local events were occurring with people dressing up for this SantaCon thing."
Demographics for the events also led Party City to add Santa styles for women - including some sexy looks - as well as accessories like antlers.
Dana Humphrey, 29, who dressed like Mrs Claus last year and is going as an elf this year, has made SantaCon in Manhattan a tradition with friends, starting with brunch, then joining SantaCon crowds for the route's first stop at a bar in the Wall Street area. Along the way, they've posed for photos at the famous Wall Street bull sculpture and done an Ace of Bass singalong with 80 Santas.
"You'll find groups of Santas doing all kinds of ridiculous things," she said.
Nigel Parry is organizing the fifth annual SantaCon in Lowertown, an artsy historic neighborhood in St Paul, Minn. The gathering drew 200 Santas last year and is accompanied by a brass band that leads revelers in and out of bars.
One of the first stops is billed as an "all ages" event at the Black Dog Cafe where parents can bring kids. But how do you explain to a wide-eyed five-year-old why there are 50 Santas, not just one?
"That's up to the parents to get creative," Parry said. "Some just say, 'These are not real Santas - they're just dressed up as Santa.'"
Some customers "come in early and stake out their seats" just to watch, said Sara Remke, co-owner of the Black Dog Cafe. "It's very much a spectator event."
But most SantaCons stress that they are not for kids, and Sibley says that's part of the appeal.
"The holidays tend to be family oriented and adults get squat," Sibley said. "They work hard all year and extra hard over the holidays. So when you get a costume on like Santa, the pressures of the real world are lifted. You have this strange camaraderie because everyone is dressed like you."
People in Hainan enjoy warm weather