Bolstered by larger smartphone screens and a growing desire to shop online, eMarketer analysts are expecting e-commerce sales this holiday shopping season to grow 17 percent over the same period last year.

Moreover, the firm expects digital sales to garner more than 10 percent of total retail sales. The company said it defines the holiday shopping season as the months of November and December. The company sees total retail sales rising 3.3 percent in this period to over $884 billion with the online portion rising 17.2 percent to $94.7 billion.

“Retailers in the U.S. should not only be stocking store shelves and adding employees to their brick-and-mortar locations this holiday season,” the firm said in its report. “They also need to make sure their supply and fulfillment centers will be able to keep up with strong online demand in November and December.”

The company noted that Amazon is driving a lot of the online sales, and garnered 25 percent of e-commerce sales last holiday season. Emarketer retail analyst Yory Wurmser said the online giant’s sales “should be even higher this year, as Amazon’s revenue growth continues to outpace e-commerce growth as a whole.” From a consumer behavior perspective, the growth of mobile device use is a key driver as well.

“Bigger screens, better mobile design and simpler payment options have all contributed to this explosion of sales via smartphones,” Wurmser said. “We’re still in the early part of the smartphone commerce revolution, and the development of better app search, payment systems and commerce on new platforms should propel sales strongly in 2017.”

Wurmser said most of the U.S. retail mobile commerce — or m-commerce — growth is occurring on smartphones. “In fact, m-commerce sales on smartphones will exceed those on tablets for the first time in 2016, totaling $67.23 billion for the entire year, or 58.0 percent of retail m-commerce sales,” the report noted.