( CNN ) -- Savvy Internet users know that all the great stuff they get from the Internet us for `` free '' —the searches , the social networks , the games , even the news—is n't really free . It 's an exchange , where companies are able to take user data , sell it to advertisers , and make money that allows them to give themselves a paycheck while keeping you afloat in free digital services . So that data you 're giving away online is worth something , but have you ever taken a stab at figuring out how much ? A just-released privacy add-on for Firefox and Chrome , Privacyfix , gives it the old college try . Both Congress and the executive branch have been talking more about online privacy in the past couple years . The estimates for Google and Facebook are imprecise , as the program 's creator , Privacy Choice founder Jim Brock , readily admits . `` We wanted people to understand , it is a value exchange '' when they use these sites , said Brock . Privacyfix measures your last 60 days of activity on Google , extrapolates that to a year , and uses a value-per-search estimate . Analysts believed Google was making $ 14.70 per 1,000 searches in 2010 , and possibly less in 2011 . Of course , if you spend all your time searching for luxury hotels or mesothelioma lawyers—and then clicking through the advertised links—you 're much more valuable than the average user . Brock says his estimated annual Facebook value was a mere $ 1.68 . His daughter , perhaps unsurprisingly , is at $ 12 . His Google value checks in at more than $ 700 per year , though . The add-on also tells you how many of the websites you visit feed data back to Facebook and Google . I was surprised to see that Facebook is tracking me across 87 percent of the Internet , despite the fact that I 'm a minimal user of Facebook . Privacyfix has a checklist for Facebook privacy settings , with orange warning signs near settings that users might want to take a look at . Unless you 're a complete privacy hawk already—or you do n't care at all—you 'll probably find something new on that list that you were n't aware of . Did you know Facebook automatically shares your profile info when you visit certain sites ? Did you know your profile details are sometimes shared not just with your friends , but often with the makers of your friends ' apps ? Privacyfix also gives you a heads-up on things you should be doing anyhow , like deleting Facebook apps you no longer use so that they stop gathering data . The add-on links you directly to those Facebook settings so you can fix them immediately , navigating you through a maze of privacy options some find arcane ; it has a similar function for Google . `` I have n't had anyone go through this process who was not surprised by something [ they saw ] , '' said Brock . While it is n't Brock 's intention that all users should tightly clamp down their privacy controls , that 's what most of the users of Privacyfix have chosen to do so far , he said . Future plans include similar privacy controls for Twitter and LinkedIn , as well as a mobile app . COPYRIGHT 2011 ARSTECHNICA.COM .
New add-on attempts to measure the value of your data to websites . Facebook , Google and other sites make their money using data for advertising . Privacyfix works with Firefox and Chrome Web browsers . Comment: