Tablet shopping is gaining on PC- and laptop-based sales and blowing away smartphone shopping.

More than 60 million Americans will own a tablet computer by the end of this year, according to the State of Retailing Online 2012 survey produced in partnership by Shop.org and Forrester Research Inc. The study found that 49 percent of merchants reported their average order value from tablets exceeded sales from laptop and desktop computers and smartphones.

Consumers are likely to spend more time shopping from a tablet than from other types of devices because they are generally more affluent and knowledgeable about the latest technology, Sucharita Mulpuru of Forrester Research in Cambridge, told Boston.com. Also, product images look more vibrant on tablets. But most importantly, people often use their tablets during their "off" hours, such as when they are watching television or relaxing in bed.

"This not only increases the overall amount of time online, but the state of mind is more leisurely, when people are more inclined to browse, add more things to their shopping cart, wait for pages to download, discover items," Mulpuru said.

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