New data from the Nielsen Company indicates that about 24.7 million U.S. mobile subscribers age 13 and up watched video on a mobile phone in Q4 2010. Up from roughly 17.6 million in Q4 2009, that represents roughly 40 percent year-over-year growth. Nielsen also recorded significant growth in average time spent per user, per month. The figure is now four hours and 20 minutes per month, up 20 percent from a year earlier.
 
Teens age 13-17 spent the most time viewing video on their mobile devices. Their average time was seven hours and 13 minutes per month, just in the fourth quarter. The next age group, 18-24 year olds, wasn’t far behind. They averaged six hours and 30 minutes of mobile viewing a month. The average time dropped consistently with each older age group. The highest age group, 65 and older, averaged two hours and 10 minutes per user, per month.
 
Even though teen mobile subscribers spent the most time viewing mobile video, that age group did not have the largest viewing audience. It turns out that 25- to 34-year-olds are the largest audience of mobile video viewers. They just don’t spend as much time doing it as the younger viewers do. The second largest group of viewers were ages 35 to 49. Teens were the fourth largest viewing audience.
 
Data from comScores’s “The 2010 Mobile Year in Review” whitepaper indicates the growth in mobile media usage is “largely attributable to the growth in smartphone adoption, 3G/4G device ownership and the increasing ubiquity of unlimited data plans, all of which facilitate the consumption of mobile media.”