Holiday Gift: More Retailers Offer Jobs as Economic Vital Signs improve - video

All told, U.S. companies will hire an estimated 600,000 temporary workers this holiday season, according to outplacement firm Challenger, Gray & Christmas Inc. That's more workers added to the holiday payrolls than in the past three years.

Demand is so high for extra help that Amazon.com, the world's largest online retail, has already hired 15,000 temporary workers. It's so many extra employees that the company has even started camps in places such as Kentucky where employees can park their RVs to sleep between 10-hour shifts. They'll work until Christmas Eve for $10 an hour.

Toys R Us is also jumping on the trend, hiring 45,000 temporary employees, a 30 percent increase from last year. UPS is hiring 50,000 extra workers.