Shoppers in the Vancouver area say they’re surprised that Christmas trees and other holiday-themed items are showing up at their local Costco stores in August.

However, a marketing professor says there are reasons a retailer like Costco might stock Christmas goods five months ahead of the holiday.

John Pracejus from the Alberta School of Business in Edmonton told CTV News Channel that as many as nine per cent of Christmas shoppers say they plan to start before Labour Day, according to surveys.

He also points out that smaller retailers might shop at bigger stores like Costco in the summer so that they can re-sell the goods for higher prices later in the season.

A third reason, according to Pracejus, is that “when people are exposed to the holiday imagery – Christmas cards, Christmas music etc. -- that puts them in a certain frame of mind that might lead them to choose more extravagant purchases in other areas.”

Although stocking the merchandise early could give retailers a boost, the professor warns that shoppers may eventually get “turned off” by a “Christmas season that gets a little longer every year.”