More Americans are literally joining the club, the warehouse club. As many retailers feel squeezed by higher costs from tariffs, all three warehouse clubs, Costco, Walmart owned Sam's Club, and BJ's are opening more locations and attracting more shoppers who are willing to pay to shop in their stores. So, what's driving the trend.Clubs have long been known for cheaper groceries, gas, and bulk items. But they're attracting younger customers as they add more convenient ways to shop online, eye-catching mercha ...