E-commerce is growing rapidly at Walmart Stores Inc. (WMT) - Get Report  , a year into its renewed e-commerce and digital commitment to take on arch-rival Amazon.com Inc. (AMZN) - Get Report .

In Walmart's second quarter, reported Thursday, Aug. 17, U.S. e-commerce net sales grew 60% year over year in the quarter ending July 31, with gross merchandise volume up 67%. The online assortment expanded to 67 million stock-keeping units. E-commerce did not cannabalize in-store visits, which grew 1.3%. 

Walmart has also snapped up niche e-commerce websites, including ModCloth Inc. and Shoebuy.com Inc. In the six months ending July 31, Walmart spent $363 million on business acquisitions, net of cash acquired. The June 15 acquisition of men's clothing retailer Bonobos Inc. accounted for the lion's share of this spending, costing $310 million.

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This e-commerce push has been a focus for Walmart in the past year. On Aug. 8, 2016, Walmart paid $3 billion for online retailer Jet.com Inc., with cofounder Marc Lore taking the helm of Walmart's U.S. e-commerce division and reorganizing its operations.

All told, earnings of $1.08 per share topped analysts' expected $1.07 per share, while sales of $123.4 billion also exceeded the consensus estimate of $122.8 billion.

"Traffic increases at store level and the eCommerce growth rate are key highlights," Walmart CEO Doug McMillon said in a statement. "We are moving faster and becoming more creative as we strive to make every day easier for busy families."

Lower-than-expected full-year earnings per share guidance of $4.30 to $4.40, below analysts' expected $4.39, sent the stock down $2.8% to $78.75 in premarket trading Thursday. 

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