The combined space of all computer hard drives in the world was estimated at approximately 160 exabytes in 2006. As of 2009, the entire World Wide Web was estimated to contain close to 500 exabytes. This is one half zettabyte. This has increased rapidly however, as Seagate Technology reported selling a total capacity of 330 exabytes of hard drives during the 2011 Fiscal Year.
In 2013, one expert estimated that the amount of data generated worldwide would reach 4 zettabytes by the end of that year.
The world's technological capacity to receive information through one-way broadcast networks was 0.432 zettabytes of (optimally compressed) information in 1986, 0.715 in 1993, 1.2 in 2000, and 1.9 (optimally compressed) zettabytes in 2007 (this is the informational equivalent to every person on earth receiving 174 newspapers per day).
According to International Data Corporation, the total amount of global data was expected to grow to 2.7 zettabytes during 2012. This is an increase of 48% from 2011.
Mark Liberman calculated the storage requirements for all human speech ever spoken at 42 zettabytes if digitized as 16 kHz 16-bit audio. This was done in response to a popular expression that states "all words ever spoken by human beings" could be stored in approximately 5 exabytes of data (see exabyte for details). Liberman did freely confess that "maybe the authors [of the exabyte estimate] were thinking about text".
Research from the University of Southern California reports that in 2007, humankind successfully sent 1.9 zettabytes of information through broadcast technology such as televisions and GPS.