China's online retail sector set to surpass US'

The Internet is becoming a central part of life, said Nettesheim. The average online time per user increased from 2.8 hours to 3.6 hours a day between 2008 and 2011.

Chinese users spend about an hour a day more on the Internet than those in the US.

"In just a few years, China has become the largest Internet market in the world. It will shortly be the most significant, too," he added.

Zhou Yuan, senior managing director of BCG, said Chinese Internet users are willing to spend more money online, and therefore, the e-commerce business will maintain its growth momentum in the coming years.

Business-to-consumer revenues are expected to grow twice as fast as consumer-to-consumer revenues between 2011 and 2015, due to increasing demand for higher-quality goods and after-sales support.

"The rapid growth represents a once-in-a-lifetime opportunity for companies that figure out how to connect with China's digital generations," said David C. Michael, a BCG senior partner and co-author of the report.

However, most companies have not yet shifted their marketing budgets and orientation to the online world.

The share of overall ad spending devoted to the online channel is expected to rise from an estimated 13 percent in 2011 to 17 percent in 2015 - far less than the 64 percent of media time that users now devote to the Internet.