On the front wall of Yan Hongchang's house in Xiaogang village, Anhui province, is a QR code. Visitors scan the code to link to an e-commerce platform that sells agricultural products produced by local farmers and companies.

Similar codes can be seen on nearly every residence. The platform's operators said the system tracks the specific household through which visitors enter.

Yan, 75, is a celebrity in the village and beyond. Xiaogang is known as the birthplace of China's rural reform, which was initiated 40 years ago.

Because his junior high school education was the best among the villagers, Yan drafted a secret agreement, signed with red ink fingerprints by 18 residents from what was then the Xiaogang production team, to subdivide their collective farmland into family plots in the winter of 1978.

By then, the country's collective farming policy had been in force for two decades.

In dramatic contrast to the experience of living on government relief or begging, common in other parts of China before 1978, Yan's family now gets more than 20,000 yuan ($2,900) a month in revenue from online sales of agricultural products, and more from other jobs.

Although the e-commerce platform is operated by a company that came from outside the village, Yan said it seems more like their own.

"The best situation before such online stores became universal around five years ago was that visitors to our village bought 100 eggs each, but now the internet helps us sell far more," Yan said.

He mainly sells noodles and black soybeans. The village specializes in the production of grapes, mushrooms and crawfish.

Many of the residents have transferred their farmland to businesses, and either have their own business or work for others. They also act as part-time sales representatives of the e-commerce platform.

Those who continue to work on farms not only get involved in sales but also supply their own products to the company.

"My children and grandchildren all work in the village. None migrated for work," Yan said.

He said innovation has played an important role in improving the residents' livelihoods.

"After 1978, the villagers' motivation for farming rose because each household's earnings was directly related to how much they produced. Some even checked their farms during the night," Yan said.

The results were immediate. The households produced five times the volume of crops than the previous year, while the average per capita income rose by 18 times to 400 yuan, according to official data.

Xiaogang was hailed by the central government as a pioneer of reform, and the practice was applied nationwide in 1982.

Yan Jinchang, another farmer who signed the agreement, said his offspring feel proud of their unprecedented accomplishment.

"All of my seven children now work and live in Xiaogang. Some do farming and the rest operate a homestay, restaurant and public bathhouse," said Yan Jinchang, who opened a restaurant in 2008 to serve the increasing number of tourists. The business earns him an annual net profit of 140,000 yuan.

The Xiaogang experiment has shown that the internet not only helps sell agricultural products but also spreads the entrepreneurial spirit. Visitors are attracted from across the country, said Shen Renlong, the village's Party secretary.

"Earthshaking changes have taken place in Xiaogang over the past 40 years. Not even one house was built with bricks, for example, but today many families own private cars," added Yan Jinchang.