Costco delivered another rock-solid earnings report.Costco Wholesale (COST -2.92%) is one of the most dominant retailers in the world, and it continues to outpace its brick-and-mortar peers, quarter in and quarter out.Costco keeps opening stores around the world, differentiating itself from other retail giants like Walmart and Home Depot, and it's seeing strong growth in e-commerce, showing that there's plenty of untapped demand for the buy-in-bulk, big-box chain.Those trends were on display in Costco's fis ...

Costco built its brand on supermarket staples. If you wanted a truckload of toilet paper or enough ham to pack 50 sandwiches, it was the place to go. But Costco has increasingly moved beyond mustard and milk.The most well-known "surprise" in Costco's sales success strategy may be the boom in gold bars bought by its customers in recent years. But the big-box retailer is also seeing a boom in sales of saunas and sofas, many of them purchased online. In industry parlance, these purchases are termed "big and bu ...