Costco is one of the biggest and most successful retailers in the country. In this video, WSJ’s Sarah Nassauer dissects the wholesaler’s unique approach to doing business. Photo: Qian Weizhong/ZUMA Press The Economics Of How do the world's most successful companies generate revenue? In this explainer series, we'll dive into the surprising stories behind how businesses work--exploring everything from Costco's "treasure-hunt" model to the economics behind Amazon's AWS. More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com/ Visit the WSJ Video Center: https://wsj.com/video On Facebook: https://www.facebook.com/pg/wsj/videos/ On Twitter: https://twitter.com/WSJ On Snapchat: https://on.wsj.com/2ratjSM #Costco #EconomicsOf #WSJ