Walmart says its AI assistant, Sparky, is leading to customers spending 40% more than those who shop without it

At first glance, the Walmart [NASDAQ: WMT] C-suite should be living large, with the company sporting a massive $836 billion market cap and its quarterly revenues up to $187.9 billion .

Yet that's not enough for Wall Street, which sent Walmart's share price down by 9% on August 20 after second quarter performance numbers didn't meet analysts' heightened expectations.

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Enter Sparky, Walmart's secret weapon. The artificial intelligence assistant, which the retail giant says drives significantly higher customer spending among those who use the AI tool to place orders, is already a major revenue driver for the company.

"We believe AI will improve nearly every part of our business by making shopping better and our associates' work easier," Walmart CEO John Furner said on the Q2 earnings call . "Sparky is a great example. The number of customers using Sparky is up 70% from last year, and the customers and members who use Sparky for shopping spend 40% more per order than others who do not."

In his comments to analysts, Furner said someone recently told him they asked Sparky for a weekly meal plan of healthy, high-protein foods. "Within a few seconds, Sparky shared recipes and meal kits with the ability to add all the ingredients they needed to their basket with one click," he stated.

The AI agent also recognized ingredients customers had recently purchased, both online and in-store, so they didn't buy something they already owned. "It is building trust," Furner noted. "When you step back, what encourages me the most is how these areas are increasingly connected."

'Causality and correlation are different things'

Launched only a year ago, Sparky is already a driving force for Walmart's digital sales, with the company's worldwide e-commerce sales up 23% year over year as of Q2.

E-commerce industry experts say digital shoppers are growing more confident in using AI to buy products online and are just as responsible for Walmart's rising order numbers. Yet there are caveats.

"Be careful of interpreting a 40% increase in orders from Sparky users as a causal effect of the AI system to increase spending by 40%," Jose Prabhu Michael Singarayan, a data scientist at Quantum Integrators, told Moneywise. "Causality and correlation are different things."