Nearly 50% of all TV viewing comes from the heaviest 20 percent of TV viewers, Nielsen said. How heavy is heavy? They spend an avg of almost 12 hours in front of the TV a day. Since 2009, Nielsen said heavy viewers have increased their TV viewing by 8%, almost a 1-hour increase in daily viewing. More stats: heavy TV viewers are 16 percent more likely to buy a domestic car and 17 percent more likely to have purchased new clothing in the past 12 months.