Target Corp. is extending its Cyber Monday promotion to stores this year and is spreading it out over two days in the hope of it making it a smoother and bigger event.

The changes come after the Minneapolis-based retailer saw a huge response last year on the big online shopping day, which falls on the Monday after Thanksgiving. The frenzy exposed weaknesses with Target’s website, which buckled under the immense traffic and has been the focus of a lot of improvements in the year since.

Cyber Monday is a fairly recent phenomenon. The term itself was coined a little more than a decade ago and has since become a popular day for retailers to offer special online deals in order to keep the Black Friday holiday shopping binge going into the following week.

It is once again expected to be the biggest online shopping day of all time this year, bringing in 9.4 percent more sales to reach $3.36 billion, according to a forecast by Adobe Digital Insights.

Target’s evolution of its Cyber Monday deal also is another example of retailers starting various holiday shopping sales earlier in the season. Many retailers — including Target, Wal-Mart and Best Buy — will once again start their Black Friday sales in stores on Thanksgiving evening.

Similarly, in a bid to get to shoppers first, some retailers aren’t waiting until Cyber Monday to roll out their online deals. For instance, Wal-Mart will launch its Cyber Monday deals on Friday.

Target is offering the same Cyber Monday promotion as last year — 15 percent off nearly everything, but with fewer exclusions this time.

The sale, which last year was only online, will go live on its website and in stores early Sunday morning through Monday night. No online promo code or in-store coupon is required.

“The big takeaway from last year was that clearly that type of broad offer on a key holiday shopping day and time was really appealing,” said Eddie Baeb, a Target spokesman.

“Our guests love this. So let’s figure out how we can deliver this in a more meaningful way. By bringing it to stores, it makes it a much, much bigger offer, especially when you think about the percentage of guests who shop in stores.”

By also offering the same promotion in stores and over two days instead of one, it will help diffuse the crush of traffic to Target.com on Cyber Monday.

“We are hopeful a longer duration discount period will help smooth traffic onto the site and that Target has learned from prior mistakes,” Sean Naughton, an analyst with Piper Jaffray, wrote in a research note on Wednesday.

Last year’s Cyber Monday was a record online sales day for Target. But the 15 percent off sitewide deal was much more popular than executives expected — so popular that Target had to put shoppers into virtual waiting lines so the site wouldn’t crash, frustrating customers who couldn’t access the site and complained about it on social media.

Executives weren’t happy about it either. “It’s like losing the Super Bowl,” Mike McNamara, Target’s chief information officer, told the Star Tribune earlier this year.

“You got there, you’re in the final. But you’re beaten like 30-nil. It wasn’t a great feeling.”

The shaky performance put a damper on what was otherwise a big sales day. By about 8 p.m., when Target.com logged its millionth order that day, the cheer that erupted around Target’s Brooklyn Park offices was halfhearted, McNamara said.

It wasn’t Target’s first online fumble.

Its site also faltered under heavy traffic from its Lilly Pulitzer designer collaboration in April 2015.

Target isn’t the only one to struggle in keeping up with demand in big moments as online shopping has become more popular.

In 2014, Richfield-based Best Buy had to take down its site several times on Black Friday.

Even Amazon, whose website is considered the gold standard in online retailing, had trouble keeping up on its big Prime Day sales event over the summer.

Since he joined Target a little more than a year ago, McNamara, has been furiously working to upgrade Target’s systems in time for the holidays when online shopping is heaviest.

He’s hired hundreds of new software engineers, overhauled the website with new front-end and back-end systems, and has been working to expand the site’s capacity to handle big shopping events, such as Cyber Monday.

He also recently added the title of chief digital officer since the executive who previously held that role, Jason Goldberger, left the company this fall.

In late August, Target did a trial run of its Cyber Monday deal with a smaller, one-day, 10 percent off promotion in its stores and online.

The event went fairly smoothly, aside from complaints about long lines in the check-out lanes, and helped fuel a 26 percent increase in online sales in Target’s most recent quarter.

“I’m confident the site can now handle far greater volume than a year ago,” McNamara wrote in a blog post Wednesday on Target’s corporate site.

He added that he expects Target’s approach to Cyber Monday — making it the same online as in stores — to become more common across retail as the lines between in-store and online shopping blur, and shoppers expect to get the same perks regardless of where or how they shop.

“I predict we’ll start to see more and more retailers merge their online and stores strategies and promotions,” he wrote.

“In this case, that means bringing online events like Cyber Monday into physical stores.”