By the time Walmart edited, then removed the racial slur-filled ad from its website, it was too late - the Internet was already enraged.
On Monday, someone noticed an ad by a seller claiming to be Jagazi Naturals, a UK-based company that makes hair products tailored for black people.
The ad was for a wig cap, which secures hair in place under a hairpiece and anchors the accessory in place.
The size was listed as medium. The color: "n-- brown."
The ad - complete with the familiar Walmart colors and typography - raced around the Web, a racial flub that was a setback for a company that's aggressively trying to expand online sales.
Walmart and Jagazi Naturals both apologised and shifted the blame onto an unknown third-party seller.
"We are very sorry and appalled that this third party seller listed their item with this description on our online marketplace," the Bentonville, Ark.-based company said in a statement on Facebook. "It is a clear violation of our policy and has been removed and we are investigating the seller to determine how this could have happened."
Jagazi said someone had hijacked their name and that neither the wig cap nor the ad was from them.
"The real JAGAZI is a 100% black company for black people," the company said in a statement at the top of its website. "People have often used our brand name to try to sell their products. Please be aware. Very sorry for all the distress this has caused. We are feeling the pain here as well. Most shocking!"
But those statements didn't stop the combination of head-scratching and outrage directed at the companies. Many wondered how a multibillion-dollar company could be so careless.
Travon Free, a writer for "Full Frontal with Samantha Bee," pointed out that Amazon has the same product listed, minus the racial slur. (Disclosure: Amazon chief executive Jeffrey P. Bezos owns The Washington Post.)
And it wasn't just one typo, people pointed out.
The slur appeared in the product's description.
Walmart is, of course, not the first US company to be accused of racial insensitivity. Airbnb recently apologised after Native Americans called an ad about a 'Sioux-style' teepee racist. Clothing retailer Gap recently pulled an ad that people said delivered a subtly racist message when a black girl was used as a prop.
It's a delicate time for Walmart, which is engaged in a battle for online sales supremacy with the market leader, Amazon. Amazon sells 50 million products on its site including those from third-party sellers, according to the AP.
Walmart.com has thousands of such vendors, though it has never shared the specific breakdown.