In 2006, after a less than illustrious career in the restaurant business, 31-year-old Ben Zempel got a job with wholesaler Costco. That wouldn't be remarkable in itself, but Zempel has Down syndrome. Since he got the job, he's happier than ever, according to his mom, Jane. It's not just employees with a disability-all 163,000 people on Costco's payroll around the world can count on extraordinary amounts of attention. They're better paid than competitors' staff, management solicits their input on store strategy, and full- and part-time workers alike enjoy complete health insurance coverage. It all adds up to low turnover: Just 6 percent of employees decide to leave the company after more than a year. In fact, after 20 Costco staff from Melville, New York, won a $200 million lottery prize last year, only one of them quit-not because of the unexpected fortune but because at 73, he figured it was time to retire. More and more businesses are beginning to realize, as Costco has, that it pays to invest in people. Strikingly, it's companies that put staff at the top of the list that seem to be doing best. Costco ended 2010 and 2011-tough years for most companies-with hefty profits.