Facebook believes that they can do a better job at using the data they already have on their 1.7 billion members and non-members that visit their site, to better target advertising to them. Targeted advertising is a big deal, because it means that users are more likely to click on those ads, which in turn brings Facebook more cash. For example, if Facebook knows that you have been searching for a new smartphone to buy recently, and it shows you an ad for a new car, you likely won't click on it. But if you are shown an ad for T-Mobile, AT&T, Sprint or Verizon, then you are much more likely to click on it. Making it a pretty big deal for Facebook.