“Could you come up with a tool that said, ‘I do not want Facebook to use my personal profile data to target me for advertising.’?” Sandberg was asked by Today’s Savannah Guthrie. “Could you have an opt-out button – ‘Please don’t use my profile data for advertising’?”

“We have different forms of opt-out,” Sandberg replied. “We don’t have an opt-out at the highest level. That would be a paid product.”

There’s no indication that Facebook actually plans to introduce such an option, but Sandberg’s admission makes explicit that Facebook’s revenue depends almost entirely on monitoring its users’ taste and behavior. Taking that option away would require replacing ad sales with subscription revenue.

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In the same interview, Sandberg pushed back against the often-repeated but suddenly fast-spreading notion that user data is Facebook’s primary product – though on largely semantic grounds.

“That’s not true . . . we don’t sell data, ever. We do not give personal data to advertisers. People come on to Facebook, they want to do targeted ads, and that’s really important for small business . . . We take those ads, we show them, and we don’t pass any individual information back to the advertiser.”

That kind of protection, of course, benefits Facebook’s bottom line by maintaining its control over ad targeting. Facebook has taken action to change various features and policies that enabled outside actors, including partners of the election firm Cambridge Analytica, to collect large amounts of personal profile data. For now, researchers and developers can still use a variety of methods to automatically harvest large amounts of public data from Facebook.

In the same interview, Sandberg acknowledged that Facebook should have notified as many as 87 million users impacted by the improper access of data by Cambridge Analytica and its partners, and that the company may discover other, similar breaches.