Phia, an advertising startup co-founded by Phoebe Gates, daughter of billionaire Microsoft Corp. co-founder Bill Gates, bills itself as a “personal shopping assistant” that helps users find the lowest prices on a broad range of clothes and fashion accessories.
Download the Phia tool onto a web browser, use it while shopping and – voila – the so-called extension can quickly find discount codes for products. Businesses like these, known in industry parlance as affiliate marketing programs, typically collect a commission from retailers that make the resulting sale.
But according to Ben Edelman, an independent researcher and consultant who studies affiliate marketing, as well as Capital One Shopping, which makes a competing browser extension, Phia is claiming credit for online sales it didn’t actually drive, in violation of many digital platforms’ policies.
Bloomberg tested the Phia mobile browser extension across more than 50 websites and found that during the checkout process, Phia opened a background tab without user interaction and injected its own referral code that overrode legitimate referrals from other publishers. These findings were consistent with Capital One Shopping and Edelman’s independent testing and code review. Testing involved using the extension like a regular shopper and observing how it communicates with other sites and its own servers.
“The most fundamental requirement in affiliate marketing is that commission is only paid if a user clicks,” said Edelman, who has spent decades exposing what he says are deceptive practices in digital advertising. Edelman spoke to Bloomberg after reviewing Phia’s code, which is public, and testing how the extension interacts with retailers’ websites and affiliate networks at Bloomberg’s request. “The rules don’t allow fake clicks, simulated clicks, imaginary clicks or hypothetical clicks. Only a real click will do.”
Capital One Shopping, a discount shopping tool previously known as Wikibuy that was bought by Capital One Financial Corp. in 2018, highlighted similar findings from its own testing in an email sent Tuesday to retailers that raised concerns about what it said were Phia’s fake clicks or “cookie stuffing.” It attached videos that it said showed Phia’s extension silently opening a background tab linking the retailer’s website with its own affiliate code to ensure its cookie was set.
“Publishers like us are having material revenue taken,” said the email, which was seen by Bloomberg. “And advertisers like you are losing money to fake clicks.”
Capital One confirmed the authenticity of the email to Bloomberg, but declined to comment on Phia. “We view it as our responsibility” to disclose any “technical anomalies or concerning practices” identified within the affiliate marketing ecosystem, a spokesperson said.
A Phia spokesperson acknowledged the issue and said it has been fixed.
“Within the last 24 hours, we were made aware that in a recent release our codebase was causing misattributions from a subset of users,” the spokesperson said. “As soon as we were notified, our team worked overnight to identify, mitigate, and has since resolved the issue.”
Bloomberg retested Phia’s browser extension after reaching out to the company on July 7 and found it had stopped automatically claiming a referral click in all the cases where it previously had been.
The spokesperson said Phia is audited regularly by its affiliate network partners and has “always maintained compliance.” The code that enables the auto-click was introduced to the source code in December. Under affiliate marketing programs, which are widely used in e-commerce, retailers know which partner generated the sale based on a unique code the affiliate adds to their link to a retailer’s website.
Phia registered fake clicks on retailers’ websites, allowing it to replace another referrer’s unique code with its own, according to separate testing by Edelman, Capital One Shopping and Bloomberg. This allows Phia to claim a commission for sales it did not meaningfully influence.
It also breaks industry rules prohibiting cookie stuffing or taking credit for other referrers’ sales. These rules are detailed in the terms of service of many retailers, including eBay and Walmart, and major affiliate networks like Impact.com.
Impact.com said it stopped working with Phia and is conducting an investigation after “receiving reports” from a third party about its behavior, which it found to be “inconsistent with our platform policies.”
When PayPal Holdings Inc.-owned Honey faced similar allegations in 2024 and 2025, it was met with significant customer backlash and a California class-action lawsuit. PayPal disputes the allegations, but the case is ongoing.
Cookie Stuffing
Phia was launched by Phoebe Gates, 23, and friend Sophia Kianni in 2025. The company has raised a total of $43.5 million from investors including Notable Capital, Kleiner Perkins, Khosla Ventures and a raft of celebrities like Sydney Sweeney, Khloe Kardashian and Hailey Bieber. Former Meta Platforms Inc. Chief Operating Officer Sheryl Sandberg is also an investor. Representatives for Notable, Kleiner Perkins and Khosla Ventures didn’t immediately respond to requests for comment.
Phia’s app has been downloaded more than 1.2 million times in the past 12 months, according to Appfigures estimates, and is billed as a personal shopping assistant that lets you compare prices and find second-hand versions of fashion items. It also trawls the web for discount codes that can be applied at checkout.
Phia may earn a commission if a shopper uses its browser extension in a way that leads to a sale, for example, by using it to apply a discount code. But Bloomberg’s testing found that Phia’s browser extension takes credit for a sale even if no action is taken by the user. To do so, Phia utilizes the cookie-stuffing tactic – silently adding a tracking code to the retailer’s web address.
Bloomberg testing of Phia’s product and source code, carried out over the course of a week starting in late June, found that when a user is in the final stages of making a purchase, the extension will automatically open a background tab that loads Phia’s affiliate link to the retailer’s site to ensure its cookie is set. The tab is then closed within seconds. Since this happens only on a mobile web browser, users are unlikely to notice the extra tab opening.
This process happens when consumers make a purchase directly from a retailer’s website, or even if they are referred through a different ad or affiliate link. During one test, Bloomberg found that clicking on a link to Nordstrom from a Wirecutter article, “The Best 4th of July Deals Still Live,” triggered a background tab that replaced the Wirecutter affiliate link with Phia’s. The same behavior was observed when Bloomberg clicked on a Google ad from a different publisher’s website.
Phia opened automatic background tabs across more than half a dozen major affiliate networks, including Impact.com, CJ Affiliate, Rakuten and Awin, according to Bloomberg’s tests. This tactic is prohibited by each of the networks’ terms of service.
An Awin spokesperson said the company was “aware of the allegations raised and is reviewing.”
Bloomberg also observed this behavior on more than 50 major retail websites, including those of Walmart, Nike and Zara.
Swapping out the referral may lead to retailers paying Phia unnecessary fees, or Phia taking commissions meant for other publishers and advertisers. A common policy found in terms of service across the affiliate advertising industry dictates that Phia should “stand down” if another referral code is already in use by a consumer.
Bloomberg began to investigate Phia after a person familiar with the company’s technology provided Bloomberg with information suggesting the browser extension was misattributing sales. The person asked not to be identified over fear of retribution.
Bloomberg subsequently shared its results and methodology with Edelman and two other ad tech experts. Edelman ran his own tests independently, and the other ad tech experts reviewed Bloomberg’s findings and confirmed the soundness of the methodology.
This is not the first time Phia has faced troubling allegations. Last year, security researchers found that Phia was logging users’ web browsing history, including snapshots showing the content of pages visited, according to a Fortune report. This included sensitive data such as bank statements and private email accounts, which were transmitted back to Phia’s servers.
Phia said at the time that it logged web page content to “understand if the site was a shopping destination,” an effort to identify and support additional retailers as they were discovered. After security researchers notified the company, Phia stopped capturing web page content in favor of URLs.
Several other companies have faced allegations over their affiliate marketing practices. Last year, social media influencers filed a proposed class action alleging that the Capital One Shopping browser replaced their affiliate tracking codes with its own identifiers, diverting commissions. Capital One settled but denied the allegations. In the 2010s, two affiliate marketers were criminally prosecuted for defrauding eBay through a scheme that netted them about $35 million, partly based on evidence gathered for eBay by Edelman.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
