Well not in bulk to its advertisement competitors as you seem to suggest. But as a different revenue stream, data collectors sell the collected information. Don't be naive, of course they do, first customer are governments.
All corporates sell your data. You're a fool to think otherwise, data makes dosh, and you can sell any data for a price.
Data is a commodity.
There are current ten plus folk in the subway carriage I am sitting in right now. Toss me £10 and I'll give you a dataset of ten people of what colour tops they're wearing and what brand of shoe and colour.
the brightdata link is a data set scraped from Facebook, not sold by Facebook
Cambridge Analytica was the same thing, scraped from Facebook by people who voluntarily (perhaps ignorantly) gave their data to quiz apps like "what kind of horse are you?"
Facebook does not sell user data, and it never has