When Phiafounders Phoebe Gates and Sophia Kianni decided to build an AI startup, they focused on an area they understood well: online shopping.
The founders, who met at Stanford University when they were randomly paired as roommates, understood e-commerce because they spent many hours searching for the right pieces to expand their wardrobes. They realized that artificial intelligence may also help people discover, shop and purchase in latest ways. They also realized that chance was a market opportunity.
“There seemed to be a huge white space there, like what should we actually buy and why doesn’t everyone have a personal shopper in their pocket?” Gates said on stage Tuesday at TechCrunch Disrupt 2025.
The startup emerged from a class project where it proved its initial demand. However, the service was only made publicly available once Phia found a product fit for the market, Kianni says.
The tool is available as an i browser extension appallows buyers to match prices, including on second-hand items, adding a sustainability factor to their purchases.
Phia claims to integrate with over 150 second-hand platforms and has over 350 million items in its internal search database. Kianni identified that purchasing used equipment means reducing your carbon footprint by 80% in comparison with buying latest. Plus it’s cheaper.
Kianni said the service also helps users understand the value of what they are purchasing. “If you look at a $500 handbag on Phia, you can quickly understand if you can resell that item for $300 or $400? Or conversely, if it’s a fast fashion item and you buy it for $100, can it only be resold for $10? Does it depreciate immediately and lose 90% of its value?”
The startup is also developing an AI-powered shopping advisor that can help users understand value aspects corresponding to how good a deal or what the retained value of an item is perhaps, in addition to fashion basics corresponding to whether an item will fit based on the user’s previous orders and returns. The founders said the size evaluation feature is currently in beta for a small group of users.
The founders used a number of tactics to draw audiences, including an ambassador program, creating their very own content on product development, and even starting a podcast.
“Being able to get hundreds of thousands of downloads at a very low cost through the podcast and through different distribution channels was really important,” Kianni said.
Additionally, Gates said, sharing the realities of making a startup with audiences helped potential Phia users connect with the founders and their story.
“I think we had to go through an ego death,” Gates said. “At first I thought, ‘I want to look good in all of our content.’ But if you want people to engage with it and you want to create content at the scale that we need, you just have to be able to pull back the curtain.”
Gates, whose father is a father, admits she got here to the startup from a position of privilege, but says she doesn’t necessarily go to him for advice.
“So even though my dad – I think he’s a genius – he’s not the one who shops on Phia, right? Like, he doesn’t shop around for the best deal on different sites. He doesn’t compare items on his spring break bucket list,” she said.