Enlarge / Amazon boxes. (credit: Getty Images | Julie Clopper)

In a quarter in which its revenues are expected to surpass $100 billion for the first time, Amazon says it will spend $500 million on a one-time Christmas bonus for its front-line employees.

The pay bump—which will not be paid until January—comes amid plans for strike action over the Black Friday shopping weekend and growing calls for unionization.

Dave Clark, the e-commerce group’s head of operations, on Thursday said full-time staff employed in the United States from December 1 to December 31 would receive $300. Part-time workers would get $150.