China now accounts for two of the six companies with the highest online media revenues and four of the 10 fastest-growing, according to a report from the global research and advisory company Strategy Analytics.
The Digital Media Index, which analyzes revenue trends across 44 public digital media companies, shows Google at the top of the list with $31.4 billion in digital media revenues in the first half of 2014, a rise of 12 percent on the previous year.
That is more than three times that of nearest rival Amazon at $10.3 billion, up nine percent year on year.
Facebook was in third place with $5.4 billion, up 66 percent, just ahead of Chinese internet service portal Tencent at $5.4 billion, which is up 43 percent.
The Chinese web services company Baidu registered a 56 percent rise to $3.4 billion, was the other Chinese company making their way into the top six.
"A red-hot Chinese Internet market is challenging the historical dominance of U.S. companies," Michael Goodman, director of Digital Media for Strategy Analytics, said in a statement.
"The fact that there are about 2.5-times more Chinese than Americans online is a big factor so they’ve been able to hit such heights solely in a domestic market. The big question, and the key threat to U.S. global dominance, is whether they can translate this success outside China," said Goodman.
Baidu was just behind Apple’s iTunes, which saw digital media revenues of $5.2 billion, up 56 percent year-on-year.
Baidu, Alibaba and Tencent are the three big Chinese webcos collectively known as "BAT", which are revving up for major moves in the China market, as possible studio buyers, content acquirers and distribution outlets for Hollywood fare in the world's second biggest film market.
Yahoo was the only one of the world’s top 10 to see digital media revenues decline year-on-year, down 3 percent.
Between them, the 44 companies generated $85.9 billion in digital media revenues in the first half of 2014, which is a 17 percent more than the same period in 2013.
Among the 44, Chinese internet security software firm Qihoo saw the largest year-on-year rise in revenues, with a rise of 123 percent to $582 million, just ahead of Twitter, which grew 122 percent year-on-year to $562 million.
Another Chinese company, Sina, which saw revenues rise 36 percent, was the fourth Chinese company in the top 10 fastest growing, while the US companies Pandora, Blizzard Entertainment, Disney and LinkedIn complete the list.
Breaking down the figures in the index, looking at the 44 companies that publicly provide revenues by category, advertising accounts for 77 percent of digital media revenues, followed by online games at 15 percent and video (5%). Music and content delivery networks (the latter such as Akamai and Limelight who serve content on behalf of publishers) split the remaining 3 percent.
Games experienced the largest year-on-year revenue growth, rising 26 percent, followed by advertising and video, both at 24 percent growth, and content delivery networks at 21 percent. Music experienced least growth at nine percent.
"The Chinese companies have been particularly adept at generating revenues across a variety of services. The fastest mover, Qihoo, for example has done well in both advertising and Internet value-added services, driven by expansion into search and mobile," said Goodman.