If slow and steady wins the race, Sam's Club still has a long way to go.

Even so, the warehouse retailer under Walmart Stores Inc. (WMT) posted a pretty decent second quarter Thursday, Aug. 17, with $14.9 billion in sales in the second quarter ending on July 28—a 2.3% uptick compared to last year. All the while, same-store sales were up 1.4%. Walmart at large saw parallel improvements, reporting second-quarter earnings of $1.08 a share, slightly above the $1.07 a share analysts had predicted.

These numbers are favorable, but still pale in comparison to Costco Wholesale Corp. (COST) .

"Ain't no stopping Costco," Telsey analyst Joe Feldman wrote in a report in July, after the company saw 6.2% same-store sales that month.

Overall, noted the publication 24/7 Wall St., Costco's sales and profits are each about twice Sam's Club's.

But that's not to say Sam's Club is flailing behind, Feldman told TheStreet on Thursday.

"It's been performing better, the stores look better, the operational issues they're working through, they're enhancing the supply chain, and there are things that Costco doesn't do," he said, "like store pickup."

Neither Walmart or Costco could be immediately reached for comment.

More of What's Trending on TheStreet:

More from Stocks

Bank of America Rips on Earnings Beat, But Analysts See Even More Gains Ahead

Bank of America Rips on Earnings Beat, But Analysts See Even More Gains Ahead

3 Reasons Why Netflix Bulls Are Getting Their Face Ripped Off After Earnings

3 Reasons Why Netflix Bulls Are Getting Their Face Ripped Off After Earnings

Stocks End Mixed as Dow Rises, S&P 500 and Nasdaq Slip

Stocks End Mixed as Dow Rises, S&P 500 and Nasdaq Slip

Action Alerts Plus is Picking Raytheon Over Other Defense Names

Action Alerts Plus is Picking Raytheon Over Other Defense Names

Should Tesla Actually Fire Elon Musk?

Should Tesla Actually Fire Elon Musk?