A question came to my mind today when I saw a new message on Facebook indicating that to keep Facebook free, customized ads based on members interests will be shown on our profiles or dashboard. Today as well I saw a suggested list of people that I might know on LinkedIn. One of them is a friend of mine that we have never exchanged an email or even connected on social media. This friend has 0 friends on his friends list so there is no common people between us. Same question came to my mind again. How the social media and search engines are able to make this semantic networks! Google Search uses our search history to show results that might be of our interests, it also use the same information to show related ads. Google is a free search that we use and they make money out of the ads. It is a mutual benefit, we search for free and they make money from ads we see based on our search keywords. Same scenario in Social Media, so Facebook and LinkedIn, and other Social Networks use th