What would Cyber Monday be without record-busting online sales?

Retailers brought in nearly $6.6 billion, according to Adobe, which tracks data through its analytics services. That sales figure is up 16.8% compared to last year and is projected to be the largest online shopping day in history, Adobe said in a release.

Those figures are roughly in line with projections and represent a more than $2.5 billion increase since 2014, according to Adobe.

In many ways, it reflects the growth of e-commerce as an industry and as Cyber Monday has grown, digital sales have exploded throughout the entire Thanksgiving week as brick-and-mortar sales inch along or decline (but still remain hugely important to holiday sales). 

Retail Dive took a look at some of the big takeaways from the day.

1. Mobile is taking over

"Mobile Monday" might soon be the better term for the day just passed, which the National Retail Federation dubbed Cyber Monday in 2005. More consumers than ever took to their phones to snatch up holiday sales deals, according to several firms tracking the day.

Mobile set a new record with 47.4% of site visits, with smartphones making up about 40% of visits, according to Adobe. Perhaps more importantly, Adobe said mobile accounted for 33.1% of Cyber Monday revenue (smartphones specifically accounted for 24.1% of revenue). Smartphone traffic specifically grew 22.2% year-over-year, while revenue coming from smartphones — at $1.59 billion on Monday — grew 39.2% percent year-over-year, marking a new all-time high.

"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," Mickey Mericle, vice president, marketing and customer insights at Adobe, said in a statement emailed to Retail Dive. "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."

Rob Garf, vice president of industry strategy and insights with Salesforce's Commerce Cloud unit, said in an interview on Monday morning that computers' share of purchases over the shopping period fell below 50% for the first time.  

Mobile accounted for 64% of Cyber Monday sales with merchants using Shopify's e-commerce platforms, according to Shopify. That was a 10% increase from last year.

The shift to mobile follows both the adoption of the smartphone over the past decade as well as retailers' (typically larger ones) efforts to make mobile shopping seamless and painless. And that goes not just for browsing, but purchasing. "Consumers are tethered to their mobile devices," Garf said. "They don't need to wait. Retailers have made it easier to purchase on their mobile device."

Other research finds consumers sticking to their desktops. From Nov. 1 to Nov. 26, desktop computers and smartphones took roughly equal share of retail site traffic — 45% for both, with tablets taking another 10% — while desktops accounted for 62% of purchases and smartphones 26%, according to Adobe.

2. Cyber Thursday, Cyber Friday, Cyber Saturday...

Cyber Monday isn't the only game in town anymore. Sales are rising sharply across what has become "Cyber Week." Garf said that his firm projects digital sales on Black Friday to beat out Cyber Monday for the second year going. "The headliner is Black Friday," he said. "Shoppers are not waiting any more to get on their computer or device or go into the store to not only research but also to click the 'buy' button."

Adobe, meanwhile, found that digital sales over Thanksgiving week hit a record high. Nov. 23-26 brought in $13 billion in digital sales, up 14.4% to last year, according to Adobe. Thanksgiving Day specifically totaled $2.87 billion (up 18.3% to last year), and Black Friday notched more than $5 billion (up 16.9%).

Personalization services provider Criteo found that the number of online shoppers on Thanksgiving increased 5.1% compared to last year while the number of purchasers increased 26.2%, indicating, according to Criteo, that people had "already shopped around for goods and were ready to buy." The firm described Thanksgiving as a "huge day for e-commerce."

Those two big trends from the day — toward mobile and week-long digital sales booms — both follow the evolving technological landscape since Cyber Monday was coined and created. As Garf points out, the digital sales holiday once depended on workers being back at the office, where their internet connection was faster (the better for making purchases). But as both household internet speeds and mobile technology has improved, the necessity of doing "Cyber Monday" on a Monday has diminished.

3. Discounts are about as deep as they can get

At 20% to 50% off, regular price promos remained roughly flat from last year, according to retail analysts with FBR led by Susan Anderson. Only a few large retailers that the analysts covered upped their discounting game this year, including Gap Inc., Francesca's, Urban Outfitters and Chico's.

Deals tended to favor toys on Cyber Monday, with discounts reaching 18.8%, followed by TVs at 21.1% and computers at 14.7%, according to Adobe. Compare those figures to Black Friday, when discounts favored appliances, jewelry, tablets and televisions. Toys, together with apparel, were also the most likely product to be out of stock.

Some of the biggest players led their websites with electronics deals. Monday afternoon saw, at one point, Amazon's steeply discounted Echo Dot (from $49.99 to $29.99) headlining the sale. Walmart featured laptop deals under its banner promos and its Jet.com arm pushed HDTVs, Home Audio and wearable tech. (Jet also promoted discounts to Google Home devices, Walmart's voice technology platform of choice.)

4. But Walmart's discounts are getting deeper

The discounting battle is perhaps most heated between Amazon and Walmart, as Amazon looks to expand ever deeper into retail categories and Walmart tries to take a greater share of the growing e-commerce market for itself, rather than cede it to Amazon.

According to a Market Track price study conducted for Reuters, prices at Walmart's website are now on average 0.3% more expensive than Amazon, compared to 3% higher than Amazon's in 2016.

And some prices are lower, according to Reuters, such as wearable technology where Walmart's prices are 6.4% lower than Amazon this year compared to 12.6% higher in the same period a year ago; and sports and outdoor products, with Walmart's prices 1.3% lower compared to 3.5% higher a year ago.

Cowen analysts led by Oliver Chen pointed out in a November note that Walmart has been making aggressive investments in its e-commerce game, including adding SKUs, free shipping to orders over $35, new app features and easy reordering, among other improvements.

5. Free delivery is the law of the land.

But the discounts didn't stop at markdowns. Salesforce found that 85% of orders they tracked offered free shipping. Free delivery has "moved from nice-to-have to an expectation for consumers," Garf said.

Other research bears that out. According to FBR analysts, 67% of the retailers they covered offered free shipping with no minimum purchase, up from 60% last year. Others gave away shipping with some sort of minimum purchase, including Lane Bryant, Old Navy, Athleta, Urban Outfitters and Anthropologie.

Retailers shipped packages purchased on Black Friday through Cyber Monday a total of 12 billion miles, Shopify estimates.

6. Cyber Monday is an entire day

Again, the days when Cyber Monday was a nine-to-five sport taking place in the office are over. Shoppers were off to a strong start in the early hours of the day. First Data President Guy Chiarello told Bloomberg TV on Monday that e-commerce traffic was up 30% year-over-year in the early hours of the shopping day, according to Seeking Alpha. 

But Cyber Monday isn't over until it's over. Adobe estimates that three hours in the evening of Cyber Monday — 8 p.m. through 11 p.m. in each local market — would bring in more online revenue than the average 24-hour day. Conversion rates likewise peaked during the last hour of Cyber Monday (between 11 p.m. and midnight) at four times the annual average.

7. Cyber shoppers love cyber stuff

Consumers shopping online were hungry for electronics. Best-sellers included Google Chromecast, Apple iPads, Samsung Tablets, Apple AirPods and Sony Playstation VR, Adobe found. Consumers also gobbled up video games and consuls, among them Super Mario Odyssey, Nintendo Switch and Microsoft Xbox One X. Winners in toys were  PJ Masks and Hatchimals & Colleggtibles, Funko Pop, L.O.L. Surprise dolls and Ride On Cars, according to Adobe.

Price-tracking platform Wikibuy found that smart home devices and other electronics were among the best sellers on Amazon. The best sellers on the e-commerce giant's website were Echo Dot, Fire TV Stick with Alexa Remote, TP-Link Smart Plug, Instant Pot 7-in-1 Pressure Cooker and AncestryDNA Genetic Testing Kit, according to Wikibuy. 

Amazon confirmed in a press release that the Echo and Fire Stick were "not only the best-selling Amazon devices, but they were the best-selling products from any manufacturer in any category across all of Amazon.com." Amazon added that "customers purchased millions of Amazon's Alexa-enabled devices this weekend" and sold millions of Fire tablets as well.