Not to mention that it is faster to distribute information through social networks than through an official website. People absolutely love to share information with others, and it spreads out greatly. Why do you think news like the SOPA fiasco was so widespread? Because people found out about them through social networks, and in turn shared that information with others.
So like JP said, like it or not, social network sites have become a staple of how we share and distribute information, and any company that ignores it is going to be left behind.