Viewers of The Longest Day in Chang'an are particularly interested in Xi'an's museums, as they look to learn more about the culture of the city featured in the online drama.

This prompted Ctrip to develop several in-depth travel products to specific museums related to The Longest Day in Chang'an.

Ctrip tour guide Liu Guoyang, a Xi'an native, takes visitors to the Xi'an Museum to identify terracotta figurines that resemble characters from the series by their hairstyles and attire.

"Young visitors prefer better travel experiences and make holiday plans suddenly. So, a short video or a hit drama may move them," says Liu Chunlin, who heads online travel agency Fliggy's new media marketing section.

"It's the power of quality content and communication in the mobile-internet era."

Shaanxi Festival Cultural Promotion Society president Yan Jianbin recalls that few people in Xi'an paid much attention when a hit TV series featured the city two years ago.

"But this time, government bodies, cultural sites and museums have increased their awareness and are taking the opportunity to market themselves on social media," he says.