WASHINGTON, Dec. 26 (Xinhua) -- U.S. holiday sales, which lasted from November 1st through Christmas, increased by 4.9 percent from a year earlier, representing the biggest year-over-year gains since 2011.

According to the data released by Mastercard SpendingPulse Tuesday, online retail shopping jumped by 18.1 percent compared to the same period last year.

"Overall, this year was a big win for retail," Sarah Quinlan, senior vice president of Market Insights, Mastercard, said in a statement.

"The strong U.S. economy was a contributing factor, but we also have to recognize that retailers who tried new strategies to engage holiday shoppers were the beneficiaries of this sales increase," she added.

Sales of electronics and appliances increased by 7.5 percent during the year-end holiday season from a year earlier, the best performance in a decade, Mastercard said.

Clothing stores and department stores saw "modest gains," although hundreds of brick-and-mortar stores have been closed this year.

The data is based on an aggregate of all the sales activity in Mastercard's own payment network, combined with survey-based estimates for payment forms it doesn't track directly, such as cash and check.