An IDC research study sponsored by information management giant EMC provides insight into the explosive growth of digital information. IDC uses a complex formula to estimate the size of the "digital universe," the total volume of digital information that is created and replicated globally.
They say that this number reached 281 billion gigabytes (281 exabytes) in 2007, which adds up to about 45GB of digital information for each person on earth. For the first time ever, the total volume of digital content exceeds total storage capacity. IDC speculates that, by 2011, only half of the digital universe will be stored.