Dive Brief:

• Online spending between Nov. 1 and Dec. 6 rose 18.6% year over year to a record $80.3 billion — the biggest e-commerce shopping period of all time in the United States — beating last year's record $67.7 billion by nearly $13 billion, according to Adobe's latest holiday shopping update, based on its survey of more than 1,000 U.S. consumers. 

• Mobile transactions soared to $23.7 billion of sales coming from smartphones alone, growing 54.8% year over year — the highest ever — and the first holiday season when over half of visits (57.6%) came from mobile devices, according to the report. Shopping through in-store pick up of online orders has also caught on this year, growing 46% from last year, Adobe found.

• Adobe now sees U.S. online holiday shopping (Nov. 1 to Dec. 31) reaching at least $124.1 billion. A fifth of U.S. shoppers plan to do more than three-quarters of that at online giants like Amazon and eBay, up 25% over last year, according to the report.

Dive Insight:

The discounting frenzy of the Thanksgiving weekend has subsided, but discounts remain prevalent and Americans continue to spend a record amount of money online. The retailers with well-built websites and advanced fulfillment are poised to rake in most of it.

The best deals for televisions, no surprise, were found on Cyber Monday. But while prices for computers and toys are bobbing back up to normal, they remain heavily discounted. Fierce competition to capture the market share abandoned by Toys R Us is keeping prices especially low on toys, Adobe found.

As customers check off their holiday lists, out-of-stock messages are up, reaching 2.2% of product page visits, Adobe also found. "This cost retailers up to $1.9 billion in potential sales and underscores an opportunity for retailers to further optimize their inventory management to deliver better endless aisle experiences," according to the report.

Social media, with a 1.5% share, isn't driving much revenue, Adobe found. What is: Direct website traffic (the best revenue driver at 27% share of sales, up 1.1% year over year), followed by paid search (24.4%, up 4.9%), natural search (20.7%, down 4.3%) and email (20.3%, up 1.6%).

Some areas of the country have been especially busy; the states with the largest average orders by dollar value were Alaska ($166), California ($165), Washington ($160), New York ($160) and Wyoming ($158). (Higher shipping costs for Alaska likely drove shoppers to consolidate orders, Adobe said).

While e-commerce sales continue to break Adobe's previous records, however, the vagaries of online shopping could also push a record number of returns, especially in apparel, many experts warn. E-commerce return rates are three to four times higher than brick-and-mortar ones, according to e-commerce returns service provider Happy Returns.

Adobe's retail report is based on an analysis of more than 1 trillion visits to retail sites and 55 million SKUs. Adobe Analytics measures transactions from 80 of the top 100 U.S. online retailers and updates data in real-time.