I understand that talks about dynamic data (type exchanges on Twitter or Amazon), either static (type client file). They are no longer hosted on a particular server. And they are very important in terms of volume (even if the author defends himself by saying that it is a round of fact, it's his catchphrase and what I found on the back cover: more than 2.8 zettabytes, are billions of gigabytes, were traded in 2012).
Otherwise it speaks techniques bikes to describe how big data can contribute to cost savings (in short, it change your infrastructure). And there are many examples of data analysis tends to show that big data is just the latest name in the fashion of the analysis of data. We understand that there is more (with, we can make the prospective analysis and draw conclusions only to correct an existing situation) but it is embedded in a repetitive words and without roughness.