Image source: The Motley Fool. What: Shares of Skechers USA Inc. (NYSE: SKX) were slipping today, after the footwear maker posted a disappointing second-quarter earnings report. As of 12:37 p.m. EDT, the stock was down 20.8%. So what: Skechers, the No. 2 footwear seller in the country, delivered earnings per share of $0.48, down from $0.52 a year ago and short of estimates at the same level. Profits fell despite a 9.7% increase in revenue to $877.8 million as domestic shipments also slipped by 5.4% in the quarter with some business pulled from April to March. International growth, however, was strong. CEO Robert Greenberg noted economic and political uncertainty around the world and blamed a promotional sales environment in the U.S. for the weak earnings results. Foreign currency translation, additional VAT taxes in Brazil, and a fire at a Malaysia warehouse also weighed on earnings. Now what: For the current quarter, the key back-to-school selling season, management is projecting $950 million to $975 million in revenue, and COO David Weinberg said he sees "upside potential" in the quarter. Analysts, though, had been expecting $1.02 billion in revenue, and the weak outlook also helped push the stock down. A wider shift in the sneaker industry may be taking place as Nike has also been seeing its sales growth slow, with Under Armour and Adidas appearing to be taking share from them. Skechers had been a growth star at one point, but the stock is now down more than 50% from its peak last summer. The company is busy expanding internationally, but the slide in domestic sales could signal a shift in consumer tastes that may be hard to overcome. A secret billion-dollar stock opportunity The world's biggest tech company forgot to show you something, but a few Wall Street analysts and the Fool didn't miss a beat: There's a small company that's powering their brand-new gadgets and the coming revolution in technology. And we think its stock price has nearly unlimited room to run for early in-the-know investors! To be one of them, just click here.Jeremy Bowman has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Skechers. The Motley Fool owns shares of Under Armour (C Shares). Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.