The scenes at major retailers have become a Thanksgiving Day ritual: Long lines, packed parking lots and shopping carts filled to the brim with bargain TVs and gaming consoles.

But while the clamor may look the same, retailers are facing a new reality this year as they kick off the holiday shopping season: The customers visiting their stores often started browsing long before they showed up, and for many, their actual purchase will happen long after.

Shoppers today ping-pong from physical stores to laptops to smartphones, and a purchase can come via any of these avenues at any time. As the lines blur between in-store and digital shopping, retailers believe they must win over these shoppers if they are to thrive in a fast-changing retail landscape.

To capture these types of customers, some retailers plan to blitz shoppers’ cellphones with coupons as soon as they step inside a store. Others are testing new delivery options that give shoppers more flexibility — and more chances to buy.

Isha Jordan of Beltsville, Md., started her “Black Thursday” by shopping on her smartphone, swiping and tapping on her iPhone to purchase a $279 Toshiba laptop from Best Buy. By 6 p.m., she had picked up her digital purchase at the store’s outpost in Columbia Heights in the District. It was a seamless process that she says allowed her to browse on her own time but still get the near-instant gratification of picking up the computer in-store, with no ­worries that it would be sold out.

“It was easier,” Jordan said. “We just come in, get it and go.”

Research shows that shopping agnostics like Jordan — people who are not wedded to a particular shopping platform — are likely to be the biggest spenders this holiday shopping season. The retail industry buzzword for them is “omnichannel shoppers,” and stores are pulling out all the stops to win their business.

“With the increased penetration of digital usage, there’s no two ways about it: The consumer who shops across all platforms, they are the most important consumer to capture,” said Alison Paul, leader of the retail practice at the consultancy Deloitte.

Macy’s will try to hook these shoppers with coupons sent straight to their phones. To do this, the department store chain has placed 4,000 tiny gadgets across its 788 stores. The devices, known as iBeacons, look for cellphones with the proper app and send them coupons. The strategy targets tech-savvy shoppers accustomed to checking prices and conducting other research on their phones during a shopping trip.

“What we’re doing is modeling as many choices as possible so the customer can shop in any way she chooses and do the transaction anywhere she chooses,” said Jim Sluzewski, a spokesman for Macy’s.

One especially popular omni­channel effort this year is offering customers the chance to buy an item online and pick it up in a store. Retailers such as Toys R Us, Wal-Mart and Best Buy are touting this “click and collect” option as a way to get the best of both shopping channels: You can make your purchase while cozied up on your sofa, but be assured that weather or shipping snafus won’t delay your gifts. Target says that 15 percent of its digital orders are now filled this way, and it expects to see even greater demand from its last-minute Christmas shoppers. There’s a strong upside for retailers: They are able to avoid subsidizing the cost of shipping the merchandize and get the opportunity to sell customers a few additional items when they walk into the store.

Gap is launching a program this holiday season that is effectively the reverse of click and collect: Physical store shoppers at 1,000 of its U.S. outposts (Banana Republic, Old Navy and Athleta as well as Gap) can place digital orders from within the store. If a particular store is out of an item in a certain color or size, a sales associate toting an iPod Touch can search all of the stores’ online and in-store inventory and have the item shipped directly to the shopper’s home.

Retailers are using new techniques to bring shoppers into their stores and away from their computer screen on Black Friday. (Reuters)

“It gives the team in the store the full capability to interact with the customer and basically meet your needs without you having to go home and do it yourself,” said Roy Hunt, a senior vice president at Banana Republic.

There was a time when traditional retailers worried that online shopping would cannibalize their businesses. And while that fear hasn’t dissipated entirely, it’s clear that retailers now see online and physical stores as an interdependent ecosystem.

Evidence of this abounds: Wal-Mart says that 10 percent of its purchases made from mobile devices take place inside a Wal-Mart store. Best Buy reported that 40 percent of revenue in its online business now comes from orders that are picked up in stores.

And in a survey by Deloitte, about 49 percent of holiday shoppers said they would “showroom” this holiday season — meaning they would browse in a store before ultimately making a purchase online. An even larger number, 68 percent, said they would do the opposite: do the research online and ultimately make the purchase in a store, a behavior that is often called “web-rooming.”

Indeed, many holiday shoppers out on Thursday had done plenty of Web research before braving the long lines and the cold.

Marci Darby of Bladensburg, Md., queued up at the Kmart in Hyattsville, Md., by 4:45 a.m. Thursday to make sure she was near the front of the line to purchase a 46-inch TV on sale for $299. She said she wanted to see the TV in person before making such a big purchase but had done plenty of Web browsing to suss out the deals ahead of time.

“You go online to get to the idea,” Darby said.

Retailers are pinning their hopes for growth on connecting with the omnichannel shopper. In a conference call with investors last week, Target’s new chief executive, Brian Cornell, said that this was one of the key pillars of his plan to reinvigorate the company.

“As we plan for the future, we will take a channel-agnostic view of our growth, allowing our guests to interact with us where and when they want: Online, in stores and on their mobile device,” Cornell said.

Ayano Takhashi of the District left Best Buy with a bright pink Beats by Dre headphones set, having researched it online a couple of days earlier. After standing in line for two hours, she was happy to be headed back to her apartment to curl up with a cup of hot cocoa — and to shop on Amazon.com for Christmas gifts such as lotion sets and chocolate.

But at the store, she got something she can’t get from her computer screen.

“I just wanted the experience” of traditional brick-and-mortar shopping, Takhashi said.