When PhiaFounders Phoebe Gates and Sophia Kianni decided to create an artificial intelligence startup, targeting an area they understood well: online shopping.
The founders, who met at Stanford when they were randomly paired as roommates, understood e-commerce because they had spent hours upon hours trying to find the right items to expand their wardrobe. And AI, they realized, had the potential to help people discover, shop and buy in new ways. They also realized that the skill was a market opportunity.
“I felt like there was this giant white space of what should we actually buy and why doesn’t everyone have a personal shopper in their pocket?” Gates said on stage at TechCrunch Disrupt 2025 on Tuesday.
The startup emerged from a class project where it proved its initial demand. But the service didn’t go public until Phia found the right product-market fit, Kianni says.
The tool, available as a browser extension and applicationallows shoppers to compare prices, including second-hand items, adding a sustainability factor to the shopping experience.
Phia says it integrates with more than 150 used platforms and has over 350 million items in its internal search database. Kianni pointed out that buying used represents an 80% reduction in carbon footprint, compared to buying new. Plus, it’s cheaper.
Kianni said the service also helps users understand the value of what they’re buying. “If you’re looking at a $500 bag at Phia, you can quickly figure out, can you resell that item for $300 or $400? Or, conversely, if it’s a fashion piece and you buy it for $100 dollars, does it only resell for $10? Does it immediately lose 90% of its value?”
The startup is also developing an AI shopping advisor that will help users understand value factors such as a good deal or what an item’s retained value might be, as well as fashion basics such as 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 tactics to attract audiences, including an ambassador program, creating their own content about 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 the various different distribution vehicles was very important,” Kianni said.
Additionally, Gates said, sharing the realities of building a startup with their audience helped potential Phia users connect with the founders and their story.
“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 of our content.’ But if you want people to engage with it and you want to create the volume of content that we need, you have to be able to just pull back the curtain.”
Gates, whose dad is yes, that Gateshe acknowledges that he came to the startup experience from a privileged position, but says that they don’t necessarily go to him for advice.
“Well, while my dad — I think he’s a genius — he’s not the one shopping on Phia, right? He’s not looking for the best deal on different websites. He’s not comparing the items on his spring break travel wish list,” she said.
