[1] Hitwise/Google Custom Research, October 2013

[2] Hitwise/Google Custom Research, October 2013

[3] Healthcare In-Depth Interviews, Edge Research, October 2013

[4] Google Internal Data. All Devices. YoY = (10/12-9/13)/(10/10-9/11)

[5] Hitwise/Google Custom Research, October 2013

[6] Hitwise/Google Custom Research, October 2013

[7] Google Internal Data.

[8] Google Internal Data. All Devices. YoY = (10/12-€“9/13)/(10/10-9/11)

[9] Google Internal Data. All Devices. YoY = (10/12-9/13)/(10/10-9/11)

[10] comScore Video Metrix, September 2013

[11] Pew Research Center, May 2013