Phoebe Gates' AI-powered shopping app, Phia, has reportedly been claiming affiliate commissions on sales it did not actually generate, using a technique known as "cookie stuffing" to attach its affiliate code to transactions. The allegations, drawn from investigations by researcher Ben Edelman, Bloomberg and Capital One Shopping, matter because they suggest the browser extension was siphoning commissions away from other publishers who had legitimately driven those sales. Phia was co-founded by Gates — the daughter of Bill Gates — and Sophia Kianni, and launched last spring.

Edelman published a detailed technical breakdown, including a video showing Phia's affiliate link being "invisibly loaded into a second tab" on iOS after a user visited a merchant's website. The company has attributed the behaviour to a bug, with a spokesperson telling Bloomberg that a recent code release was causing "misattributions from a subset of users" and that the issue was identified, mitigated and resolved within 24 hours of the company being notified. Both Edelman and Bloomberg reported that the feature enabling the practice had rolled out in December 2025.