Publix Super Markets Inc. announced it will expand its online delivery service to all its approximately 1,100 stores within four years.

LAKELAND — Publix Super Markets Inc. announced Wednesday it will expand its online delivery service to all its approximately 1,100 stores within four years.

When that service will come to Publix’s home shores in Lakeland and Polk County has not been determined.

“We know it will happen. We just don’t know when,” said Brian West, a Publix spokesman from the company’s Lakeland headquarters. “For us in Lakeland, it can’t come soon enough.”

In July, Publix rolled out its online service as a pilot program in Miami, Tampa and Orlando through San Francisco-based Instacart, West said. Instacart has shoppers working in Publix stores who will buy the items on a client’s shopping list and deliver the groceries in as little as an hour or at a designated time up to seven days later.

It has proved so popular that the service has already expanded in Florida to Daytona Beach, Fort Lauderdale, Fort Myers, Jacksonville, Melbourne, Naples, Sarasota, St. Petersburg, Tallahassee and West Palm Beach, according to the company’s Wednesday statement. It’s also in Atlanta; Columbia, S.C.; Charlotte, Durham and Raleigh, N.C.; and Knoxville and Nashville, Tenn.

The Instacart service will be available by 2020 at all 1,148 Publix stores in those states, including locations in Northwest Florida, plus Alabama, the statement said.

West could not say when in 2020 the expansions will be completed.

But Dacyl Armendariz, an Instacart spokeswoman, said her company’s goal was to service at least 80 percent of the U.S. market by 2018. She also could not say when the service would come to Polk County.

“We have no finite timeline,” she said. “We’re expanding at a breakneck speed.”

Instacart also serves other supermarket chains, including Whole Foods and Costco, as well as retailers such as Petco and Orlando-based ABC Fine Wine & Spirits.

Using Instacart requires setting up an account online through a computer or phone app, Armendariz said.

The customer then selects items and designates a delivery time, she said. The shopper will purchase all items in the store from fresh meat and produce to packaged items.

For a single delivery, Instacart charges $5.99 for orders of more than $35, Armendariz said. For orders from the minimum $10 up to $35, it charges $7.99.

But Instacart also offers unlimited deliveries for a $14.99 monthly charge or an annual fee of $99 to $149, depending upon location, she said.

The move represents Publix’s attempt to keep up with the competition in an expanding online marketplace, said David Livingston of DJL Research, a Wisconsin supermarket analyst and consultant.

Retail giant Walmart, which owns the largest U.S. supermarket chain, already has announced its plans to greatly expand its online services, including a controversial move to use store employees to deliver items, he said.

Cincinnati-based Kroger and the Meijer supermarket chain based in Michigan also offer the service in some stores.

And then there’s online shopping king Amazon, which has begun expanding its food offerings, Livingston said.

While smaller, Publix’s reputation for service and quality puts it in a good position to compete online with behemoths such as Walmart and Amazon, he added.

“If you had a choice to buy groceries someplace, would you buy from Amazon or Publix? I think Publix has a good name. Would you give it up to Amazon?” Livingston said. “I think Publix can do a better job than Walmart, or at least keep up with it. I think Publix sees it as shameful to lose one dollar to Walmart.”

But neither West or Livingston would say online shopping represents the future of the industry.

“Personally, I think it will be difficult for some people to let go and not go into a store,” West said. “They want to go into a store and pick out the fresh fruits, vegetables and meats themselves.”

“What it means to brick-and-mortar stores, I just don’t know,” Livingston said.

The service will likely attract more tech savvy customers, such as Millennials, he said. Livingston cited his 36-year-old sister, who prefers online shopping to taking her three children to the store.

The service could also prove popular to seniors who know how to use computers and smart phones, and can’t go shopping because of physical limitations, Livingston added.

But the service doesn’t have to be widely popular to have a financial impact, he said.

If it meant even an additional 2 percent in sales at five local Publix stores with an average $600,000 in weekly sales, that’s another $60,000 in revenue, Livingston said.

“It’s like having one big customer,” he said.

Other supermarket industry analysts agreed online shopping has already had a significant impact that will likely grow.

“There is no doubt there is a strong consumer demand to have such an offering,” said Jon Springer, a senior editor for Supermarket News, in an email to The Ledger. “It is a big time saver and plays to a ‘convenience’ megatrend. Many, not all, people today value the time they save by shopping online and removing tasks like grocery shopping, which can free up a few hours every week they can otherwise spend on their family or work or whatever.”

Springer agreed the market isn’t big yet, but Publix still needs to compete in it.

“To the extent it’s a ‘response’ to Amazon, it’s only that they know they need to have a strategy for e-commerce for those of their customers who want it,” he said. “Otherwise they risk losing sales to those who do offer that in their markets.”

Springer and Lorrie Griffith, editor in chief at The Shelby Report, another industry publication, agreed Publix took the move to compete with Amazon and other supermarkets moving online.

“I certainly believe it’s in response to competitors offering online shopping and delivery,” Griffith said in her email. “Kroger offers the service in some of its stores, and it has been well received.”

West and Shelby noted Publix experimented unsuccessfully with online shopping and delivery 20 years ago and that the market may have finally matured.

Change often comes to the market slowly, but it does arrive, said Livingston, who noted people once commonly got their milk and dairy products through a milkman’s daily deliveries to their doorstep.

“It’s taken the internet 20 years to get to this,” he said. “I don’t know if it’s the future, but it’s a trend that’s growing.”