Even Facebook doesn't have demographics and user info. on all of its users, as this ReadWriteWeb story illustrates. In particular, look at the comments which point out all of the problems with using an incomplete set of data.
Facebook doesn't require users to provide age, geographic location and other basic demographic data when they sign up. Thus, the user data you get when you go through the self-serve advertising program doesn't include all of those people who didn't submit data. And you don't know how many, or how these missing people differ.
Also, Facebook doesn't require people to update their data, which causes other problems. One of the ReadWriteWeb story commenters noted that students who graduate from a high school or college may or may not be counted as students.
Facebook data should not be used for planning your social media strategies and services. You're better off guessing than using this data. Bad data may
Continue reading “Using stats from Facebook’s self-serve advertising program”