In a surprising disclosure during Monday’s testimony at the Justice Department’s antitrust trial, Kevin Murphy, an economics expert for Google‘s parent company Alphabet, revealed that Google pays Apple a hefty 36% of the revenue generated from search advertising through the Safari browser. The revelation, which was intended to be confidential, was made by Murphy, a University of Chicago professor, much to the discomfort of Google’s main litigator, John Schmidtlein.

Both Google and Apple had been adamant about keeping the details of their agreement under wraps. In a recent court filing, Google argued that divulging more information about the deal could “unreasonably undermine Google’s competitive standing in relation to both competitors and other counterparties.“

Related /

• A decade ago, Apple called Android a ‘massive tracking device’
• What you need to know about Google’s antitrust trial and your search behavior
• Satya Nadella accuses Google of unfair practices in high-stakes trial
• Apple’s Search Engine Ambitions Stifled by Google’s Secret Payments?

The partnership between Google and Apple dates back to 2002, designating Google as the default search engine on Apple’s Safari browser. Today, this agreement holds immense significance, as it dictates the search engine for the iPhone, the most widely used smartphone in the United States.

The Justice Department is honing in on this longstanding agreement, using it as evidence in its case against Google, alleging that the tech giant is unlawfully perpetuating its dominance in both the search engine and search advertising markets. The trial is shedding light on the inner workings of these tech giants and their complex relationships as they navigate the landscape of antitrust regulations.