Amateur fashionistas mingled with models and celebrities on Thursday as they broke out their stilettos - and their wallets - for the fourth annual Fashion's Night Out.
The celebrity-studded night was designed to lure shoppers into stores for celebrity spotting, music, giveaways, food and drinks, and, of course, shopping.
By early evening in New York, the basement beauty floor of Bergdorf Goodman was packed.
Madeleine Russell of Manhattan, wearing her FNO shirt from last year, got her nails done ahead of a long line. She's been attending FNO events every year since 2008.
"I'm inspired by all the fashion around me and I get my own ideas," she said.
Like the FNO pro she is, Russell planned to head home from Bergdorf to put on make-up and her Manolo Blahniks to see Cyndi Lauper at the Blahnik store later in the evening.
The event - launched in 2009 in New York by Vogue editor-in-chief Anna Wintour - has proven so popular that it's now a fixture in 19 countries; over three weeks involving tens of thousands of shoppers.
In New York, Kim Kardashian was signing $123 gift sets of her perfume True Reflection at Lord & Taylor, while Nicole Richie and Jennifer Hudson promoted their new clothing lines at QVC and Lauper promoted her new musical, Kinky Boots.
By dusk in Paris, the luxury shopping district was awash with thousands of people - both the serious shoppers and those who just wanted to enjoy themselves.
"There are too many people here to buy clothes. But people get to know the brands, and buy another time. Today, it's all about fun," said Corine Marneffe, 50.
Chloe produced one of the best spectacles in Paris: A parade of dancing cheerleaders who descended in camp style from a Chevrolet truck.
In London, models Yasmin and Amber Le Bon (wife and daughter of Simon) were walking in a fashion show at the Westfield shopping centre along with Lizzy Jagger (daughter of Mick).
Does all the starpower and hoopla help at the register? "Ask me tomorrow," Max Azria said with a laugh backstage before his BCBG presentation at New York Fashion Week. He said it couldn't hurt to meet shoppers.
Stores across the US are also holding events, though they're less star-studded. In Chicago, Saks Fifth Avenue will offer free cocktails, hors d'oeuvres and music; in Atlanta, Lenox Square Mall is giving out gift bags, will hold a fashion show at Banana Republic and offer make-up touch ups at Aveda. In Dallas, fashion shows were planned at Galleria Dallas and NorthPark Center, where the Neiman Marcus will show The September Issue, provide snacks and a contest for a $2500 gift card.
The event, timed for the first day of New York Fashion Week, also coincides with the final night of the Democratic National Convention. A Vogue spokeswoman said the event was planned a year in advance with thousands of retailers.
She said Wintour is a supporter of President Barack Obama and noted that shoppers had five hours of events - plenty of time to get home to watch Obama speak if they wished.
NBG Productions analyst Brian Sozzi said Fashion's Night Out started inconspicuously but had gained traction over the years.
"It gets customers into stores in a non-peak hour after work and it gets them energised," he said.
"It's a win-win for retailers who are piggy backing on Fashion's Night Out's own marketing so it's not a big investment for them."
On Twitter, Fashion's Night Out's hashtag, #FNO, was one of the top trending keywords.
Laura Ashley tweeted about goodie bags while designer shoe label Christian Louboutin shared a special Fashion's Night Out Spotify playlist.
Kelly Talamas, director of Vogue Mexico & Latin America, said that last year's Fashion's Night Out boosted local sales. For its second year, Fashion's Night Out Mexico more than doubled the number of participating stores, to 250 from 100 in 2011.
FNO Mexico will also expand to the Mexican city of Guadalajara, where activities will be held on September 13.
"Mexico is one of the strongest countries in the fashion scene, there is knowledge about fashion and interest in shopping," Talamas said.
"All the brands representatives told us that they sold a lot. There were some who said to us: 'Wow, we sold more than ever. This has been the most successful day in the year'," she said.
Talamas said those brands included Fendi and luxury watchmaker Jaeger-LeCoultre.
In Paris, Fashion's Night Out is also an opportunity for young fashion designers to showcase their work. Rising star Anthony Vaccarello - now a staple fixture of the Paris fashion-week calendar - moved into trendy boutique Colette for the evening to show off his new work. It included an exquisite one-shoulder white satin gown.
"Here in Paris it's about window shopping, looking, celebrating fashion. In New York, the emphasis is on purchasing. It's just two different styles of the same evening," said Vaccarello.