• Walmart will become the third-biggest online retailer in America in 2018, according to eMarketer’s latest forecast.
  • The ranking was done in terms of revenue, and Walmart had to overtake Apple to do it.
  • There is still a large gulf between Walmart and Amazon in eMarketer’s data, however, and it is predicted to widen even more.

Walmart just hit a major milestone in its quest to become one of the country’s largest online sellers.

The company just leapfrogged Apple to become the third-biggest online retailer in America in 2018, according to eMarketer’s latest forecast.

According to eMarketer, by the end of this year Walmart will have 4% of all online retail sales in the United States, up from 3.3% last year. In terms of dollar value, those sales would total $20.91 billion. Ahead of Walmart is eBay, with 7.6% of US online sales.

Walmart’s sales numbers include the websites for Walmart and Sam’s Club as well as Jet.com. The company has posted strong online growth numbers over course of the year.

Walmart has been aggressively expanding its online offerings to take a bigger bite of the market.

"Walmart's e-commerce business has been firing on all cylinders lately," eMarketer principal analyst Andrew Lipsman said in a statement. "The retail giant continues to make smart acquisitions to extend its e-commerce portfolio and attract younger and more affluent shoppers. But more than anything, Walmart has caught its stride with a fast-growing online grocery business, which is helped in large part by the massive consumer adoption of click-and-collect."

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It's not all good news for Walmart, however, as the giant Amazon still looms large over the online shopping sphere. Emarketer estimates the company will rake in $252.10 billion domestically, up just over 29% from 2017. That's good for a 48.0% share of US e-commerce - up from 43.1% in 2017.

US ecommerce will grow 16% to reach $525.69 billion overall, eMarketer estimates, or 9.8% of total US retail sales this year.