What happened

Shares of Dollar General Corporation (NYSE:DG), a low cost retailer of products such as food, beauty aids, cleaning supplies, and other basic items, are down 8% as of 11:30 a.m. EDT Thursday after the company released weaker-than-expected first-quarter results.

So what

Dollar General reported a 9% increase in net sales, driven partially by a 2.1% increase in same-store sales. That $6.11 billion total revenue was a year-over-year improvement but still fell short of analysts' estimates calling for $6.18 billion. Diluted earnings per share checked in at $1.36 during the first quarter, which was also short of estimates calling for $1.40 per share.

A look at products down an aisle of a retail store.

Image source: Getty Images.

"Our team delivered strong net sales growth, a solid same-store sales increase, and gross margin expansion, while continuing to execute our cost containment strategy," said Todd Vasos, Dollar General's chief executive officer, in a press release. "We are proud of our execution and solid performance, particularly given the significant weather-related headwind we faced during the first quarter."

Now what

Management put part of the blame for its weaker-than-expected quarter on the weather. The company believes an unusually cold and damp season negatively impacted same-store sales in certain categories, but the truth may be that the brick-and-mortar chain is finally starting to lose some ground to e-commerce competition. That said, one quarter doesn't make a trend and investors will want to keep an eye on the company's same-store sales growth for a better idea of its business health.

Daniel Miller has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.