Yesterday's national day of online shopping therapy for single people may have healed some lonely hearts, but for the mainland's delivery workers it meant a lot of pressure to get the packages out on time, as well as a handsome bonus. Some couriers said the shopping bonanza would bump up their monthly wages by 50 per cent. "I make about 3,000 yuan [HK$3,790] a month on average, but this month I think it's going to be at least double that," said Li Fenglin , a 27-year-old worker with Yunda Express, one of the mainland's biggest courier firms, in Beijing. But the extra pay comes at a price. Li estimated he would have to handle about 100 items a day this week - twice the usual number. "We're under a lot of pressure to deliver the packages on time. Hours are very long this week, but I think since it's Singles' Day, I don't mind serving such customers," he said. A worker with the courier firm Shentong Express said the industry had to rely on temporary workers to keep up with demand. The State Post Bureau said the week would be the busiest of the year for logistics companies. Last year some failed to meet their delivery deadlines. More than 323 million packages would be handled between yesterday and Saturday, with nearly a fifth processed on the first day - double last year's busiest day, the bureau estimated. As a result, courier firms have been jostling for more staff. Recruitment websites, including 58.com and Ganji, are still advertising positions, hoping the higher than usual pay will bring the desired response. Industry group the China Express Association said the mainland's 13 major couriers would add about 4,000 temporary vehicles to their regular fleet to deal with the volume, along with 30 per cent more air freight. Shentong, which is based in Shanghai and moves shipments for Alibaba's online shops, said it had hired more than 45,000 temporary workers to help its regular staff of 150,000. SF-Express, a leading courier based in Shenzhen, took receipt of a Boeing 757 freighter at the end of last month in part to ensure capacity for the big spree. Zheng Liying , an analyst with iResearch, said courier firms had prepared better for what has become a "crazy shopping festival" than last year, when many shoppers experienced delays. "One of the things they've done this time is to secure enough people to get the things out to customers," she said. The marketing gimmick, which used to target mainly consumer-to-consumer business, has become increasingly a business-to-consumer one, making it less relevant for individual sellers than big companies, she said. Tmall.com a spin-off of the Taobao online shopping service, said its logistics partners had hired as many as 100 planes to handle the increase in orders. The mainland's express delivery trade was going through rapid growth, the post bureau said, with total revenue amounting to 185 billion yuan in the first three quarters, up 27.2 per cent over last year.