"You can almost tell the future 'look' of Tencent's mobile empire as it is expanding to verticals based on its WeChat platform," said Lu.

According to Lu, the Hangzhou-based Alibaba is cutting into the mobile Internet market with mobile payments service Alipay Wallet, which has more than 100 million users.

"Alibaba has invested in a vast range of companies, covering taxi-booking, wealth management, mapping services and social media, including its own mobile chatting app Laiwang and Sina Weibo, a micro-blogging service in which Alibaba has a stake," she said.

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Compared with aggressive expansion by Tencent and Alibaba, Baidu seems "a little bit quiet in mobile expansion", Lu added.

In the past year or so, Baidu bought app store 91 Wireless for $1.9 billion and took control of the group-buying website Nuomi. Prior to those deals, Baidu invested in an online video site and online travel site.

Analysts said that Baidu's key advantage in mobile is its own mapping service. Based on that, Baidu can integrate many location-based services, from food and restaurants to hotel booking and group-buying functions. But they said it seems that Baidu has been slow in terms of the integration and expansion.

Tian Hou, chief analyst with T. H. Capital LLC, an independent research and investment advisory firm, offered another take on the acquisition spree.

"The most important thing for the three giants to succeed in the mobile era is to maintain their core advantages in the PC era," said Tian.

"Tencent's biggest asset in the PC era was its users, because the company specialized in social media. Alibaba's biggest asset was small and medium-sized enterprises, given its e-commerce empire. Baidu's advantage has been traffic, since it's a search giant," Tian said.

Tencent is maintaining its user numbers through WeChat; Baidu still has an advantage in traffic, generated by 14 apps instead of just one important portal. Alibaba, however, hasn't figured out how to maintain its former advantage, she said.

Alibaba's e-commerce empire in the PC era is like a closed circle. "Inside the circle, there are suppliers, buyers, platforms, payment functions, and everything.

"It is an ecosystem, no one can get out if they want to be in e-commerce in China," Tian said, adding she can't visualize another such circle for Alibaba in the mobile era, at least not yet.

But does "the present" predict "the future" for the three Internet giants? Not necessarily.

"I cannot predict their performances tomorrow based on their establishment today, as the landscape of the Internet industry can change overnight," she said.

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