• by Laurie Sullivan , Staff Writer, October 6, 2025

It may be Mozilla's turn to shine, given its focus on privacy for so many years and the changing consumer climate around trust.

Mozilla has designed and built a programmatic ad-targeting model from the ground up to give advertisers access to its Firefox audience, while ensuring that data privacy and user trust remain core to the platform.

It has partnered with Index Exchange, a supply-side platform (SSP) that serves as a programmatic marketplace for media owners to sell digital ad inventory.

“We’re stepping into the field that we have long critiqued,” Mozilla.org COO Suba Vasudevan, who left Meta Platforms after 11 years to join the company and build this platform, told MediaPost. “We will prove to the industry you can truly build and deliver outcome-based advertising without giving up on trust.”

Ad inventory will become available exclusively via its Private Marketplace (PMP) deals through the independent ad exchange Index Exchange, its first U.S. partner to launch programmatic advertising on Firefox's New Tab.

Mozilla’s Firefox U.S. user base is small, but Vasudevan hopes this will change with the focused Index Exchange partnership.

The most recent market share data from Statcounter Global Stats puts its U.S. user base at around 4.15% as of September 2025, between 9 and 10 million Firefox users in the U.S.

To help grow this market, Mozilla acquired privacy-focused tech company, Anonym in mid-2024 as a starting point to ensure it could build out this model.

It uses technologies such as confidential computing, which protects data in use by isolating computations within hardware-based Trusted Execution Environments, and differential privacy, a mathematical framework that collects and analyzes data while guaranteeing strong protection for individual privacy.

Mozilla will provide advertisers with anonymized, privacy-safe campaign measurement and insights without tracking individual users through these methods.

Privacy is one focus, and trust in ads is another. Not knowing where and when ads run has been a problem with platforms.

Vasudevan sees a new future for advertising through this privacy-compliant collaboration with Index Exchange.

“This is a new future of ads monetizing the internet, but with generative AI there will be a different narrative and tone,” Vasudevan said. “The big pendulum swings through the ad industry, do we want privacy, do we not want privacy.”

Mozilla and Index Exchange are co-creating the new programmatic model, which represents a step toward giving advertisers proof of where and when ads serve in a privacy, compliant way.

The ad model will flip. As data regulations tighten around the world, consumers have begun to ask questions about their privacy and AI.

“It's become clear advertisers can no longer build practices that have been in place for the past 10 years,” she said. 

The Mozilla and Index Exchange partnership will provide native advertising as a way to align performance goals with user trust in the fastest-growing programmatic channel, which the company estimates is about 88% of global spend. Ads will not have personal identifiers.

Firefox research shows that privacy-minded users expect some level of personalization when it improves their experience — but only if delivered responsibly and with user control.