NEW YORK—The holidays are coming and Amazon plans to add 120,000 seasonal workers in an effort to meet an expected spike in demand as more and more people trade bricks for clicks.

The seasonal positions will be created at fulfilmentcentres, sorting centres and customer service sites in 27 states. The move marks a 20 per cent boost from the 100,000 seasonal hires a year ago.

The move comes as online shopping growth continues to eclipse shopping at traditional stores. The National Retail Federation, based in Washington, D.C., is forecasting holiday sales for the November and December period to rise 3.6 per cent to $655.8 billion, much better than the 3 per cent growth seen in the year-ago period. Online shopping is expected to rise 7 to 10 per cent over last year to as much as $117 billion.

Ever since capacity problems in 2013 caused some people to get packages after the holidays, Amazon has been pouring money into its distribution centres and logistics chain, opening new distribution centres and leasing its own planes and trucks to speed up delivery.

At the end of July, the company said it has 123 distribution centres globally and more than 23 sorting centres, with plans to have add 21 new global fulfilmentcentres by the end of September; at the same point in 2015, it had added only 10.

Last year, the company said it transitioned 14,000 seasonal positions to regular, full-time jobs and it expects to boost that figure this year.

By contrast, brick-and-mortar stores holiday hiring has been relatively flat from the prior year.

Macy’s plans to hire about 83,000, Kohl’s Corp. plans to hire 69,000 additional workers and Target Corp. says it will hire more than 70,000, all about even from a year ago.