Such a move would have been a major shift away from the policy of not selling Facebook members' information, which the social network has stressed in the face of criticism alleging it is more interested in making money than protecting privacy.
During testimony before Congress in April about the company's data handling practices in the wake of the Cambridge Analytica scandal, Facebook CEO Mark Zuckerberg said: "I can't be clearer on this topic".
A Facebook spokeswoman confirmed the discussions about charging for data and said the company ultimately decided against it. But they provide a window into mostly sealed court filings - which a British lawmaker has pledged to make public next week - from a lawsuit against Facebook filed by a company called Six4Three LLC.
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Taken together, the internal emails show the company discussing how to monetize its user data in ways that are employed by some other tech firms, but that Facebook has said it doesn't do.
In 2015, Facebook shut down a feature known as an API that allowed developers to see data about the friends of Facebook users that had installed.
The suit accuses Facebook of abusing its power over user data.
Applications were suspended "due to concerns around the developers who built them or how the information people chose to share with the app may have been used", according to a blog post.