- Alex Palmer, Nielsen Business Media

NEW YORK Viewers are looking for laughs on their iPhones and Blackberrys, according to a new study from the Nielsen Co. Comedy is the top category in mobile video viewing, per the Mobile Video Report, a quarterly study that measures mobile subscribers who view TV or video clips on their cell phones, Blackberrys and other mobile devices.

Drawing from a sample of 3,348 viewers, the report finds that after comedy, weather ranked as the second highest video category, with sports, music and news/finance filling out the top five.

Mobile viewing is quickly growing in popularity, with a 20 percent increase in viewership since last quarter’s study. More than 60 percent of those watching video on their mobile devices are below the age of 35, with 70 percent within the significant 18-49 demographic.

NBC took the top spot in the brand ranking (with a 40.1 percent share of viewers), followed by Fox (38.3 percent) and MTV Networks (32.9 percent). YouTube ranked fourth in the brand rankings, but came in at the top of the channel rankings (29.4 percent), followed by the Weather Channel (28.9 percent), Fox (27.2 percent) and Comedy Central (25.8 percent).

While sports was the third highest category, sports brands scored relatively low in the brand rankings, with Turner Sports Entertainment coming in sixth and ESPN tenth in brands.

Viewers watch mobile videos for an average 13 sessions each month, at about 15 minutes per session. Teens under the age of 18 watch significantly more, averaging 20 minutes each session for 22 mobile sessions each month.

The gender split was more equal in teens than in viewers in other demographics, where viewership among women falls below that of men.

Adweek is a unit of the Nielsen Co.