Phia’s founders on how AI is changing online shopping

when FiaIts founders Phoebe Gates and Sophia Kiani decided to create an AI startup, targeting an area they understand well: online shopping.

The founders, who met at Stanford when they were randomly paired as roommates, understood e-commerce as they spent hours searching for the right items to expand their wardrobes. And AI, they realized, has the potential to help people discover, shop and buy in new ways. They also realized that capability is a market opportunity.

“There seemed to be this huge white space, like, what should we actually be buying and why isn’t there a personal shopper in everyone’s pocket?” Gates said on stage TechCrunch Disrupt 2025 tuesday

The startup emerged from a class project where it proved its initial demand. But the service didn’t roll out to the public until Fia had the right product-market fit, Kiani said.

Tool, available as a browser extension and AppAllows shoppers to compare prices with second-hand items, adding a sustainability factor to the shopping experience.

Phia says it integrates with more than 150 second-hand platforms and has more than 350 million items in its in-house search database. Kiani notes that buying second-hand represents an 80% reduction in carbon footprint compared to buying new. Plus, it’s cheap.

Kiani says the service helps users understand the value of what they’re buying. “If you’re looking at a $500 handbag at Phia, you quickly realize, can you resell that item for $300 or $400? Or, conversely, if it’s a fast-fashion piece and you’re buying it for $100, is it only reselling for $10? And does it lose 9% of its value?

The startup is also developing an AI shopping advisor that will help users understand value factors like a good deal, or what an item’s holding value might be, as well as fashion basics like whether the item will fit based on the user’s previous orders and returns. The founders said the Sizing Insights feature is currently in beta with a small group of users.

Founders have used a variety of strategies to attract audiences, including an ambassador program, creating their own content about product development, and even starting a podcast.

“The ability to achieve hundreds of thousands of downloads at very low cost through podcasts and various distribution vehicles was really important,” Kiani said.

Also, Gates said, sharing the reality of building a startup with their audience helped Phia’s potential users connect with the founders and their stories.

“I think there was an ego death that we had to go through,” Gates said. “At first, it’s like, ‘I want to look good on all our content.’ But if you want people to engage with it and you want to create the amount of content we need, you have to be able to pull back the curtain.”

Gates, whose father Yes, that GatesAdmits he comes to the startup experience from a position of privilege, but says they won’t go to him for advice.

“So, when my dad — I think he’s a genius — he’s not shopping on Phia, right? Like, he’s not looking for the best deals across different sites. He’s not comparing items on his wish list for his spring break trip,” she said.