TechCrunch: In its newly released Visual Networking Index (VNI), Cisco predicts that IP traffic will climb from 369 exabytes in 2011 to 1.3 zettabytes in 2016. In other words, 2016's network traffic will exceed the cumulative traffic from 1984 and 2012.
The reason Cisco expects so much traffic growth is the proliferation of devices. By 2016, they predict 18.9 billion Internet-connected devices--that's 2.5 for every person on earth.
While those numbers are staggering, comparing actual numbers to Cisco's previous VNI forecasts shows that the company is actually a little conservative in its estimates; actual traffic has generally been higher than Cisco predicts.