A recent clothing swap, it may have looked more like a Silicon Valley launch party because no one brought their old clothes, just their smartphones. Parties like it are actually happening every day in cyberspace using an app called Poshmark.
Founder Manish Chandra says the app addressed a problem in his own life.
"When I walked into our closet, I saw shopping bags that my wife had that had never even been opened, let alone used," he said.
So he created something that is like a cross between Instagram and eBay to turn those clothes into cash.
Users take a photo and enter a few details and then followers can view the items and buy them with just a click.
One user says it's so easy, it's addictive.
"Everything was done with the phone," Tracy Ho said. "You take the photos with the camera that's on your iPhone and you list it straight from your phone, and I thought that was like the easiest way to do it."
Poshmark is only for women's fashion, but the number of women using it is doubling every six weeks.
Crossing the room in her bright pink shoes, VentureBeat reporter Meghan Kelly says Poshmark users spend 25 minutes a day using the app -- even more than Facebook. And unlike Facebook, Poshmark won't have any trouble turning a profit.
"They're making money, they're taking a fee off of each of these purchases, and that's, and people are buying," she said.
By the end of the year, Poshmark expects $500 million will have changed hands, making the app more than just a passing trend.