Boxes move along a conveyor belt at an Amazon Fulfillment Center on Cyber Monday in Tracy, Calif. (Reuters/Noah Berger)

While retailers have been deluging customers for days now with a steady stream of holiday shopping promotions, shoppers still came out in droves for Cyber Monday, with early data showing that e-commerce sales for the day were on track to soar 9.4 percent over last year.

As of Monday morning, some $540 million had already been spent online, according to Adobe, whose software runs under many retailers’ websites. And while Cyber Monday has long reigned supreme as the biggest day of the year for digital shopping, it faced a stiff challenge from Black Friday this time around. Retailers were on track to pull down $3.36 billion online on Monday, which would just barely edge out the $3.34 billion spent the previous Friday.

It perhaps shouldn’t come as a surprise that Black Friday sales figures are rivaling those of Cyber Monday. After all, the idea of starting your online shopping on the Monday after Thanksgiving is a vestige of the pre-smartphone era, of a time when people weren’t able to do much digital browsing and buying until they parked themselves in their cubicles after a long weekend of travel and hanging out with family.

This year, some 55 percent of visits to retail websites on Black Friday were made from mobile devices, suggesting that swarms of shoppers got the digital spending spree started early. And retailers gave them plenty of reason to: Walmart started its Cyber Monday deals on Friday, and Target offered two days of Cyber Monday, with a “15 percent off your purchase” offer that was in place for both Sunday and Monday.

And for shoppers who missed the deals bonanza, it looks like retailers still have a steady drumbeat of promotions planned for the coming days. The websites of Macy’s and Target were touting a “Cyber Week” slate of deals, suggesting that Monday would hardly be the only day for scoring digital discounts. And Amazon.com had earlier declared it was offering “more than 35 days of Black Friday” this year.

These patterns may also help explain why social media mentions of Cyber Monday have fallen a staggering 82 percent compared to last year: People have already gotten their goods, or they’re planning to hold out for the next round of discounts.

Adobe said that the top-selling gadgets for the early part of Monday included the Sony PS4, Microsoft Xbox, and Samsung 4K televisions. In the toy department, Lego, Shopkins and Nerf were among the strongest sellers.

Some major retailers offered hints on Monday as to how those trends were playing out on their sites: Walmart said bestsellers in the early part of the day included big TVs, such as a Samsung 60-inch LED set, as well as toys from Nerf and Shopkins. JCPenney, meanwhile, said on Twitter that toys were “driving strong traffic online” and were among the most searched-for items on its website.

Target, meanwhile, offered a summary of what items were selling strongly on Sunday, the first day of its Cyber Monday promotion.  Popular purchases included Sony Playstation and Xbox gaming consoles, KitchenAid mixers and the Apple Watch. Amazon reported Monday afternoon that it is on track for its highest-grossing Cyber Monday in history. Its connected home gadget, the Echo Dot, is its best-selling item for the day so far. (Jeffrey P. Bezos, the chief executive of Amazon, owns The Washington Post.)

For the full holiday season, the National Retail Federation is projecting that online sales will grow some 7 to 10 percent over the previous year, easily outpacing the 3.6 percent growth the trade group expects to see for the industry overall.

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