Zhao Ying, a local Shanghai tour guide, led a group of 14 tourists from Taiwan to the 2010 World Expo on May 1, the first day of the park's normal operation.

"The tourists, either family members or office colleagues, ordered the tickets online several months ago for the visit to the Expo park on the opening day."

After entering the park through the long queues at the entrances, Zhao Ying introduced them to the highlights of the Expo and areas of restaurants, then guided them to the pavilions where they booked visits in advance.

She said during the Expo, her workload will be much heavier.

"Before, I only worked about two weeks a month on average. But now, as long as I am not on sick leave, I will be here every day."

Zhao Ying was not sure how many tourists she would serve in the following months, but said customers can now only order Expo tours at her company for those taking place after June.

Zhao Ying's company carried more than 60 groups to the Expo site yesterday as the park received more than 200,000 visitors in total. More than 70 million visits to the site are expected before the Expo ends on October 31, including 3.5 million by overseas tourists.

Tang Lan, sales director of Ctrip.com, a leading internet-based travel agency headquartered in Shanghai, believes the Expo will bring huge opportunities to his company as well as all domestic tourism-related sectors.

"Tourist inflow will not only contribute to the revenue rise from Expo ticket sales, but also benefit transport and hotel industries. Visitors from other parts of China may also tour scenic spots near Shanghai, while foreign tourists may fly to other cities after enjoying the Expo."

He said travel agencies can increase profits by designing Expo tours into certain product packages.

"We can not only offer an Expo tour guide, but also extend our services into areas like hotel and air ticket booking. In addition, we can also incorporate the Expo site visit with tours around places of interest in and out of the city."

Since the Expo will last six months, Tang Lan expected tourism enterprises can earn more from the Expo than during the Olympic Games.

Tang visited the Expo Park on April 20 when the trial operations commenced. He was deeply impressed with the creative structures there and some of precious exhibits in the pavilions.

However, he pointed out that the Expo will also challenge the organizers in terms of managing visitor flow, offering long-lasting high-quality services and improving park facilities.

"I was disappointed on that day. Visitors were squeezed out of the fully packed subway carriages and swarmed to the entrances where they then waited a long time for security checks. In toilets, there weren't even wastebaskets. Organizers have done improvement in later days, but there is still a lot of work ahead."

Tang said the Expo offers a rare opportunity for China's tourism sector, which is expected to be one of the country's new pillar industries in several years, and that it will further boost China's rising influence in the world.