While White called those gains "impressive," sales for that week were still well short of the season's biggest days. According to Adobe's data, Cyber Monday revenue hit an all-time high for a single day, at $3.07 billion. It was followed by Black Friday, which generated $2.74 billion, and the second Monday of December, known as "Green Monday," which rung up $1.89 billion in sales.
According to Adobe, online retailers posted 31 billion-dollar days during the holidays, all of which were between Nov. 22 and Dec. 22. That compares with 25 such days last season. Overall, holiday sales accounted for 28 percent of annual online sales, Adobe said.
Fueling the growth in online revenues was a larger-than-expected shift to mobile, which White attributed to a larger adoption of smartphones.
Whereas tablet traffic declined from a 14 percent share in 2014 to 11 percent in 2015, smartphone's share grew from 30 percent to 39 percent. Desktop traffic declined from 56 percent to 50 percent share.
In terms of sales, phone revenue grew 52 percent to $14 billion, while those from tablets fell 3 percent to $9 billion. On desktop, revenue rose 4 percent to $60 billion.
Though desktop remained the largest driver of visits and sales — at 50 percent and 73 percent, respectively — there were six days when traffic from smartphones surpassed that from desktop. Prior to this holiday season, that had never happened, according to Adobe.
White said the days that skewed toward smartphones tended to be on the weekends and as Christmas drew closer, when shoppers did not necessarily have access to desktop computers, White said.
On Christmas, when traffic from smartphones peaked at 49 percent of digital visits, it nearly surpassed traffic from desktop and tablet devices combined.
"That's a big deal," White said.