retail for the entire holiday may be overestimated based on these early numbers.
Scot Wingo, chief executive of e-commerce company ChannelAdvisor, calls the early online shopping season Cyber 5, referring to Thanksgiving, Black Friday, Saturday, Sunday and Cyber Monday.
The online players are definitely participating more on Thanksgiving and Black Friday, so Cyber Monday is being shared with other holidays now, Wingo said.
ChannelAdvisor clients saw same-store sales on Amazon.com jump 35 percent on Thanksgiving and 38.3 percent on Black Friday, compared with a year earlier.
Client same-store sales on eBay's online marketplace rose 27 percent on Thanksgiving and 31 percent on Black Friday, compared with a year earlier. Last year's year-over-year growth was about 15 percent for eBay, according to ChannelAdvisor.
EBay usually grows more slowly early in the holiday season and then ramps up later as retailers run out of hot products and shoppers turn to eBay sellers for those items.
EBay's strong start this year is driven partly by the company's success in attracting mobile shoppers through shopping apps on smart phones and tablets, Wingo said.
EBay said on Saturday that the volume of mobile transactions on its online marketplace jumped 153 percent on Black Friday, compared with a year earlier. PayPal, the payments division of eBay, saw Black Friday volume almost triple, year over year.
Purchases from mobile devices accounted for 16.3 percent of online sales on Black Friday, up from 9.8 percent in 2011 and 3.2 percent in 2010, according to IBM data. Apple Inc's iPads and iPhones led the charge, with owners using the devices to browse and buy on retailer websites.
SHOPPERS 'WANT TO SPEND'
Overall, the percentage of sales from online shopping is expected to rise. But while retailers bring in more revenue from online shopping, they may also face some higher costs in terms of shipping a larger number of packages to more shoppers.
Among tablets, iPads were the clear leader, generating 88.3 percent of traffic to retailers' sites on Friday, followed by Barnes & Noble Inc's Nook with 3.1 percent, Amazon.com Inc's Kindle with 2.4 percent and the Samsung Galaxy with 1.8 percent, IBM said.
It's either going to be a much bigger holiday or people are shopping earlier in the season, said Wingo. We won't know until later in the season.
Stores continued to use discounts to lure shoppers on Saturday, with Aeropostale Inc discounting items as much as 70 percent after a storewide 60 percent discount on Friday.
Rival American Eagle