NEW YORK ( TheStreet) -- Online retailers had a great holiday season, led by  Amazon (AMZN - Get Report) .

According to market researcher comScore, online retail sales in the U.S. (on desktop only)  increased 15% year-over-year during the holidays. Consumers spent $53.3 billion on shopping online (desktop only) during the season, with $2 billion spent on Cyber Monday alone.

ChannelAdvisor (ECOM - Get Report) , a company that makes e-commerce software for online retailers, reported that its customers' online sales (desktop and mobile) increased 16.2% during November and December. That exceeded predictions from IBM (IBM - Get Report) of 13.9% growth.

"We believe that including mobile, online sales likely increased 16-17% Y/Y, coming in above the high end of our forecast for 14-16% Y/Y growth," Cantor Fitzgerald analyst Youssef Squali wrote in a research note. "Overall, we view the data as broadly positive for the health of group and shows that the secular growth story for online Ad/Ecom names remains intact."

ChannelAdvisor reported that Amazon's same-store sales rose 26.9% during the holiday season. ChannelAdvisor defines same-stores sales for Web retailers as sales from merchants who have sold their goods on a Web site for at least one year. 

Squali doesn't expect the growth to slow anytime soon. He expects Amazon's North America sales to increase 23% in the fourth quarter, compared with 25% growth in the third quarter, and expects Amazon's gross profit will increase.

EBay (EBAY - Get Report)   lagged Amazon during the holidays, with a 7.3% increase in same-store sales, including 5.8% growth in December and 9.8% in November. 

"This growth trails the 16% growth in overall e-commerce and indicates that eBay may be continuing to see some negative impact from the security breach, which hit eBay in late May," Squali wrote.

Growth of eBay's Marketplaces has been stalling since the beginning of 2014, according to analysts. Its number of active buyers, transaction volume and revenue growth pale in comparison with Amazon. Add the holiday numbers, and things aren't looking too promising for the company, compared with Amazon. 

Written by Rebecca Borison in New York

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