How do the owners of Facebook make so much money if it's free to use?

[wordscantdescribeme]

I understand it's free to sign up for face book, so you don't pay any money.

I know the owners have advertisements on their site, but are the advertisements really the reason how all 3 of them became billionaires?

[Hamza N]

The advertisements you see on the side

[Aftershock]

The Advertising.

[philly]

Advertising. People pay to have ads placed on facebook.

[ThreeDaysOfGrace]

Theres probably a lot of reasons but all i can think of is for Ad's for such a big audience.

[Rach]

Because of the obviously HIGH amount of visitors... companies know that people will be viewing the pages, so pay facebook to post their advertisements etc. (notice them all on the side bar?)

[Shannon]

yeah businesses pay big bucks to get their ads on facebook so tons of people can see

[animalgurl]

advertising and when you play games if u want to buy more money on games you have to pay

[Johnny5]

Advertisements, with over one and a half billion users they make a fortune on ads.

[Phillip Gigliotti]

advertisements, promotions, organizations buying into facebook, celebrity pages, business pages, company pages, fundraisers, etc.