The Monday after Thanksgiving, nicknamed Cyber Monday, was the largest online shopping day in history for U.S. retailers, with $6.59 billion worth of goods sold – a 16.8% increase from the year before.

Adobe Analytics, which measures 80% of the online transactions from 100 of the largest major U.S. retailers, also reported overall web traffic to retail sites increased by 11.9% on Cyber Monday, with the season average at 5.7%.

Mobile device use for shopping set a new record, representing 47.4% of visits (39.9% smartphones, 7.6% tablets) and 33.1% of revenue (24.1% smartphones, 9% tablets). .Smartphone traffic grew 22.2% year-over-year. Revenue coming from smartphones, which totaled $1.59 billion, saw 39.2% growth year-over-year, a new all-time high. (Story continues below.)

Mobile transactions are closing at a 12% higher rate than Cyber Monday 2016. For purchases made on smartphones, Apple iOS led with an average order value of $123, in comparison to Google Android at $110.

Shopping and buying on smartphones is becoming the new norm and can be attributed to continued optimization in the retail experience on mobile devices and platforms, according to Mickey Mericle, vice president of marketing and customer insights at Adobe.

“Consumers are also becoming more savvy and efficient online shoppers. People increasingly know where to find the best deals and what they want to purchase, which results in less price-matching behavior typically done on desktops,” Mericle said. “Millennials were likely another reason for the dramatic growth in mobile, with 75% expecting to shop via their smartphone."

The holiday shopping season so far, from Nov. 1 through Nov. 27, has driven a total of $50 billion in online revenue. Adobe predicts this will be the first-ever holiday season to break $100 billion in online sales.

The figures were released the same day as one from a retail industry group that showed from Thanksgiving Day through Cyber Monday, more than 174 million Americans shopped in stores and online, beating the 164 million estimated shoppers from an earlier survey by the National Retail Federation (NRF).

Average spending per person over the five-day period was $335.47, with $250.78, or 75%, specifically going toward gifts. The biggest spenders were older Millennials, those 25-34 years old, at $419.52.

“From good weather across the country to low unemployment and strong consumer confidence, the climate was right, literally and figuratively, for consumers to tackle their holiday shopping lists online and in stores,” said NRF President and CEO Matthew Shay.

Retailers’ technology investments paid off, with consumers shopping on all platforms through the long weekend. The survey found that more than 64 million shopped both online or in stores. In addition, more than 58 million shopped only online, and more than 51 million shopped only in stores.

The multichannel shopper spent $82 more on average than the online-only shopper, and $49 more on average than those shoppers who only shopped in stores.

The most popular day for in-store shopping was Black Friday, cited by 77 million consumers, followed by Small Business Saturday, with 55 million consumers. The top two days that consumers shopped online were Cyber Monday with more than 81 million and Black Friday with more than 66 million. In addition, 63% of smartphone owners used their mobile devices to make holiday decisions, and 29% used their phones to make actual purchases, according to NRF.