Over 40% of US mobile users now report daily usage of a second screen device while watching TV

"64% of smartphone owners and 70% of tablet owners multi-task while watching TV several times a week or daily
The average consumer is watching over 5 hours of video per day, an increase of 1 hour per week (+4%) in 2 years
40+% of mobile users now report daily usage of a second screen device while watching TV; 29% of viewers report looking up program-related information and 20% report looking up ad-related information while watching TV."

Source:  Data from VivaKi’s The Pool, reported by Lost Remote, 17th Oct, 2013

Full report here