(Bloomberg Gadfly) -- It's been almost three years since China's online advertising market looked so robust, according to earnings announcements from three major players.
Sina Corp. and its subsidiary Weibo Corp. reported fourth-quarter financials late Tuesday, followed by Baidu Inc. early Wednesday.
What's particularly telling about this growth is that it doesn't seem to have been driven by excessive increases in marketing budgets. That's a huge difference from Alibaba Group Holding Ltd., which reported a 90 percent increase in its sales and marketing spend, compared with just 56 percent revenue growth. Despite being labelled an e-commerce company, Alibaba gets most of its revenue from advertising and so such a comparison is reasonable.
You can see Sina's improved scale in its declining cost of ad revenue as a proportion of sales in that category.
If you break out Weibo, the trend continues to play out with a consistent decline in the expense ratio. Baidu, which has a higher cost basis, is also enjoying some economies of scale.
Increased mobile engagement is a constant also, with Baidu telling investors that time spent on its mobile app rose 30 percent during the period. Baidu gets almost all of its revenue from advertising, so such upside must benefit ad spend across its offerings.
After years marveling at the ability of Chinese companies to make money from content, social networks, and games -- Tencent Holdings Ltd. being the prime example -- it's quite a turnaround to see that advertising is actually cool again.
This column does not necessarily reflect the opinion of Bloomberg LP and its owners.
Tim Culpan is a technology columnist for Bloomberg Gadfly. He previously covered technology for Bloomberg News.
©2018 Bloomberg L.P.