In 2009, global digital data topped 800,000 petabytes and was projected to reach 1.2 million petabytes in 2010. Storing 1 million petabytes on DVD would generate a stack of discs that reaches the moon and back. However, that rate of growth—62% in one year—pales compared with IDC’s prediction that the figure will top 35 zettabytes (36.7 million petabytes) by 2020, or 44 times as much as 2009. That stack of DVDs would reach halfway to Mars.
(following graphic originally posted by Tech News Ninja here)