Costco (COST) has surprised investors not with spectacular growth or disappointing failures, but it's resilience to those very ups and downs. Though profits were up last quarter, revenue was slightly less than anticipated. Overall, this lead to slightly less growth than other retail chains that benefited from the increased spending in February. Interestingly, these small changes are why investors are buying stock in Costco. It's loyal customers have proven themselves to be a known quantity regardless of where the market shifts, which appeals to those looking for long-term dividends.