I had a group dinner with Albert-László Barabási a few weeks ago and had the opportunity to ask him to what extent modern social network services like Twitter and Facebook were employing network science under the covers. He was pretty skeptical that they were doing anything that interesting.<p>Which is certainly bourn out by this article.<p>My gut feeling is that of all of them, LinkedIn is doing the most interesting things, perhaps because it has the biggest stake in actually understanding the relationships between graph-distant members. With their more ad-oriented models, Facebook and Twitter have much lower fruit available to them in the form of mining user product sentiment and likely ad demographic.