Megaretailer Costco (NASDAQ:COST) has produced many happy returns for investors. Shares of Costco have risen by about 40% over the past five years, outperforming competitors such as Wal-Mart (NYSE:WMT), BJ's Wholesale Club (NYSE:BJ), and Target (NYSE:TGT). Berkshire Hathaway (NYSE:BRK-B) Vice Chairman and Costco board member Charlie Munger has said that "virtually none of the sins of modern capitalism are at Costco."

Costco CEO Jim Sinegal recently stopped by The Motley Fool to talk about his supersized business. In this first of three video installments, Sinegal talks about one way he checks out his competitors.

Coming Thursday: Jim Sinegal on his greatest weakness.

Listen to the entire audio interview of our conversation with Costco Jim Sinegal at www.motleyfoolconversations.com, or subscribe through iTunes.