US mobile shoppers spent more than $10 billion in the first half of 2013, in a segment making strong inroads in retailing, a survey showed Tuesday. The comScore survey showed retail sales from consumers using smartphones or tablets in the first half rose more than 25 percent from the same period a year ago and now account for 9.5 percent of all digital ecommerce sales. \"While mobile devices are already extremely influential in the overall buying process, they are also beginning to drive a meaningful percentage of digital commerce,\" said comScore chairman Gian Fulgoni. \"One out of every ten consumer e-commerce dollars is now spent using either a smartphone or a tablet, and growth in this segment of the market is outpacing that of traditional e-commerce by a factor of 2x, which itself is growing at rates in the mid-teens.\" The report showed \"m-commerce\" revenues, which are highly seasonal, at $5.9 billion in the first quarter and $4.7 billion in the second quarter. With the largest spending likely in the fourth quarter, sales are on track to top last year\'s pace of $20 billion. The report said smartphones accounted for some six percent of e-commerce sales in the first half of 2013 and tablets for 3.5 percent. The biggest categories for m-commerce were apparel and accessories, computer hardware and event tickets. Video game, consoles and accessories showed the highest percentage of digital commerce spending via m-commerce at 23.7 percent, according to comScore. More than half of US adults own a smartphone, and about one-third have a tablet computer, according to recent surveys.