So, a Zettabyte is a thousand Exabytes, which, as I’m sure you know is a thousand Petabytes; which is a thousand Terrabytes; which is a thousand Gigabytes. Which I think means a Tettabyte is a trillion gigabytes. Anyway, by 2012 according to the rather excellent white paper, Approaching the Zettabyte Era from Cisco (.pdf here), about half a Zettabyte of data will flow over the internet each year. The main driver for this, as you might suspect is Video. YouTube in 2008, for example, is responsible for more data than the whole of the internet in 2000.They are predicting three surges in video consumption. The first - internet to the PC (which we’re in the middle of); the next internet to the TV (barely begun) and finally video communications.The net result is they’re forecasting that video over the net will increase sixfold by 2012. And, while we’re chucking around hand stats nuggets as a result: the internet will be 75 times bigger in 2012 than in 2002.