Facebook sign up is free . Then how Mark make such a big profit out of Facebook?

[Shiva]

[Seb]

Advertisements, games,

[ScottP]

By advertising, people pay money for the advertisements on the right hand side. Or they pay money to promote their page in the newsfeed thats pretty much what the "your friend liked .." is, advertising which companies pay for.

[Sam]

yes advertisements through stimuli and exposure, games as incentive in attracting consumers, selling consumers information to buyers such as Google. also using users information and posts which is used for marketing, theres the old saying anything you post online can be seen any anyone in the world, privacy settings means nothing. Theres also the old economic saying, anything free is not free' aka could lead to furthering inertia, processes in buying. facebook is a commodity

[Naveen]

by adds only...it cost 39 -40 dollars/month for posting adds in facebook,not oly facebook earns profie,youtube,google,also follows the same... :-)

[Janmejai]

You Can see lots of ads in the right side and now they also offer Facebook pages to promote their pages by paying.