How does a free website such as facebook actually make money?

[stando]

[Joe]

Companies pay to advertise on their high-traffic website.

[jntc]

They make money by advertising. Not sure if they are a publicly traded co. or anything, but it's probably mostly the advertising.

[Sammi Wowza]

Unsurprisingly, Facebook makes most of their money off of advertising
Facebook offers two types of advertisements: self-service ads and engagement ads. The first type are fairly simple: they consist of a title, picture, and a bit of text, and the user can click the link or "like" the advertisement. Engagement ads are more complex; they allow for things like surveys that let the user interact with the advertisement.

Facebook also displays a large number of Microsoft ads (due to a 2007 ad deal); as of 2009, that spending had reached $50 million

also with apps and facebook gifts hope i helped!