Final numbers are in for Cyber Monday, and they reflect mobile’s growing influence on retail and consumers’ shopping habits.

Shoppers spent $6.59 billion online on Cyber Monday compared with $5.65 billion last year, a 16.8% increase, making Cyber Monday the biggest U.S. online sales day. according to Adobe Systems Inc. The 16.8% increase is in line with Adobe’s projection and based on its precise sales numbers ($6.59 billion and $5.65 billion are rounded).

Revenue generated by smartphones accounted for 21.2%, or $1.40 billion, of online sales on Cyber Monday—also a record, according to Adobe. Mobile sales, which includes smartphones and tablets, generated $2.0 billion in sales, or 30.3% of overall revenue, and 47.4% of total traffic.

“Smartphones have become the de facto device for mobile shopping, while tablets continue to be more used as entertainment and gaming devices,” says Taylor Schreiner, director of Adobe Digital Insights. “Consumers take smartphones everywhere, including work, and have a broad range of screen size options that make mobile shopping convenient and easy.”

“Millennials were likely another reason for the dramatic growth in mobile, with 75% expecting to shop via their smartphone,” says Adobe vice president of marketing and customer insights Mickey Mericle. “Shopping and buying on smartphones is becoming the new norm and can be attributed to continued optimizations in the retail experience on mobile devices and platforms.”

U.S. consumers have spent a total of $50.01 billion online since Nov. 1, with 32.6% of those sales, or $16.3 billion, coming on mobile devices, Adobe says. Smartphones have accounted for 22.4% of total online revenue, or roughly $11.2 billion, while tablets have accounted for 10.2% ($5.1 billion). Shoppers are on pace to spend a record $107.4 billion online this year in the U.S., with each day since Nov. 1 driving more than $1 billion in online revenue. Mobile devices have accounted for 46% of online traffic through the start of the holiday shopping season.

Meanwhile, e-commerce software provider BigCommerce Pty. reports that mobile accounted for nearly half (49%) of sales done by its merchant clients from Thanksgiving through Cyber Monday. Merchants selling on its platform experienced an average of 21.8% year-over-year growth in gross merchandise value, or the value of goods sold through its platform, over the five-day span from Thanksgiving through Cyber Monday (Nov. 23-27), with Thanksgiving posting the highest growth at 24% and Cyber Monday with the lowest growth rate at 18%.

While BigCommerce merchant clients posted the smallest year-over-year sales growth on Cyber Monday, Cyber was the most lucrative in terms of average order value. Shoppers spent an average of $114.10 on Cyber Monday, up 7.4% from $106.24 last year. Black Friday was a close second for average order value, with shoppers spending an average of $106.20, up 7.6% from $98.70 last year.

Among more than 200 clients of e-commerce technology provider Workarea, mobile traffic (smartphones and tablets) held steady at 55%-56% throughout the holiday weekend, which indicates that shoppers are not switching from mobile to desktop to shop from work, school or home on Cyber Monday, says Linda Bustos, the vendor’s director of merchant strategy. “Online retailers should consider that mobile marketing channels like social, push notifications and mobile search ads are opportunities to increase traffic, with increasing confidence this traffic can be converted,” she says.

Mobile (smartphones and tablets) posted big gains among Workarea clients for Cyber Monday, with revenue increasing 31% year over year compared with desktop revenue gains of 23%. Smartphone traffic dipped below 50% only on Cyber Monday at 47%, with the following shares through the rest of the weekend: 55% on Thanksgiving,  56% on Black Friday, 57% on Saturday and 54% on Sunday, Workarea reports.

Other key points from the Thanksgiving weekend:

• Amazon.com Inc., No. 1 in the Internet Retailer 2017 Top 500, reported that the five-day stretch from Thanksgiving through Cyber Monday was its best ever, declining to specify overall sales figures. Amazon reports that shoppers bought more of its Echo Dot voice-enabled personal assistants and Amazon Fire TV Stick devices than any other product on its site throughout that time period.
• Payments processor First Data reports that online sales accounted for 29% of overall sales for its clients on Thanksgiving and Black Friday, up from 25% last year.
• The International Council of Shopping Centers (ICSC) reports that 69% of shoppers who opted to pick up an online order in a store on Black Friday wound up buying something else while picking up their online order. 25% of shoppers surveyed opted for in-store pickup of an online order that they placed on Thanksgiving or Black Friday. ICSC based its findings on a survey of 1,016 U.S. adults on Nov. 25.
• Cyber Monday had 2.3 times (127.1%) more online shoppers than the average day in 2017, with 7.5 times (655.3%) more orders placed, according to personalization vendor Qubit, which analyzed data from almost three dozen retailers and millions of shopper interactions. Sunday was a slower day during the holiday weekend, with the lowest proportion of new shoppers (53.9%) and the lowest conversion rate (2.73%), but it had the highest average order value ($91.89), according to Qubit. Thanksgiving had the highest proportion of new visitors (56.8%), as consumers checked out online stores they had not browsed before.
• There were  422,782 Cyber Monday-related terms and hashtags across Twitter that had a potential reach of 10.2 billion globally, and 48% of those messages were posted from mobile devices, according to Sprout Social, a social media software vendor. Black Friday-related messages and hashtags on Twitter were far more popular, totaling 2.07 million with a potential reach of 29 billion globally, and 63% of those came from mobile devices. Sprout Social’s social listening tool, which also analyzes sentiments in social media posts, found that emotional response was 65% positive, with #bestprice and #deals among the most positive hashtags.
• In the United Kingdom, online shoppers spent 1.39 billion pounds ($1.89 billion) on Black Friday, up 11.7% from 1.24 billion pounds ($1.66 billion) a year ago, data from e-retail association Interactive Media in Retail Group (IMRG) shows. That 11.7% growth figure outpaced IMRG’s projected 9% year-over-year growth in online sales for Black Friday. IMRG reports that 39% of Black Friday online revenue, or 542.1 million pounds ($724.7 million) was transacted via smartphones, which was higher than sales on desktops or tablets.