@Navnit Kundu - Facebook uses trackers to cross reference your browsing history. So even if you don't have Facebook open, other sites with Facebook like buttons and scripts will record and deliver targeted ads.
A fundamental rule when using any web app that is free is to ask yourself : why is it free? How will the company pay for it's network infrastructure, staff and offices?
It is because YOU - the user are the product.
Eg : Mr. X uses Facebook, Mr.X has his work info, his relationships, his friends, his political views, his travel history - all of it posted on Facebook.
Now, say you are an insurance company and Mr X wants to sign-up for a policy. Don't you think Facebook will (at a price of course) provide insights into Mr. X's life events? Based on the profile. the insurance company can charge Mr.X premium as per their criteria.
If this seems too paranoid, read this (this was before Facebook went public and listed on stock exchange):
How Facebook Sells Your Personal Information
http://www.seeker.com/how-facebook-sells-your-personal-information-1766411494.html
Facebook expects personal data sharing to double every decade and plans to target members' information more closely.
Now that Facebook has gone public and is struggling to get a steady valuation, the company is looking to find new ways to make its money and prove its worth to investors.
One option Facebook is exploring is enhancing ad sales by more effective targeting of increasingly specific demographic groups, using
location data from mobile devices and information culled from the site.
The company will be targeting members' information more closely, and expects personal data-sharing to double every decade.
That forces Facebook members to consider just how much of their
personal information to share, both now and in the future.
How might Facebook's already flexible privacy policy change as the company works harder to become a platform for engaging with brands? How will that affect the end user?
Marketing Treasure Trove
We have to start by taking a look at the data in question. How much of a danger to the consumer is the data that Facebook has? Exactly how much data does it really have?
Peter Pasi, executive vice president at Emotive LLC, an Arlington, Va.-based firm that focuses on digital outreach for political campaigns, says Facebook has quite a bit.
"Facebook is the largest opt-in community of individuals in the world, and boasts unparalleled reach," Pasi said. "In English, that means it's likely the
largest database of people ever built, and contains more personal data than any other source."
We know that Facebook has a lot of information about us, both what we enter ourselves and the data that our friends choose to put up about us.
Remember the last time your friends tagged you at a location and posted photos? They were sharing your personal data with Facebook.
What Marketing Companies Look For, and How Much They Can Use
"Online marketers look at signals," Pasi said. "Did someone visit a snowboarding vacation site, or put a new snowboarding jacket in their online shopping cart and not buy it? Have they been searching for snowboarding equipment? These are the types of things that signal a marketer that a consumer is interested in, or intent on, making a purchase."
You can see how quickly information that seems innocuous when you post it on Facebook can make you a target for specific marketing goals.