The most tireless corporate development outfit in town is at it again.

Yahoo today acquired its 19th startup since Marissa Mayer assumed the top job. The company acquired Beijing-based Ztelic, which analyses data from social websites.

A Yahoo spokesperson confirmed the acquisition to the Wall Street Journal, adding that it was a small “talent acquisition,” and Ztelic’s eight employees will join Yahoo’s research and development in Beijing.

Ztelic founder Hao Zheng, a former Yahoo China employee, will split his time between the offices in Beijing and Sunnyvale.

The terms of the deal remain unknown. It is also unclear whether Ztelic will continue to operate, but it’s unlikely given that Yahoo has shuttered most of startups it acquires. Ztelic’s homepage now features little more than an announcement of the acquisition.

In her first year as CEO, Mayer is already responsible for almost a quarter of the acquisitions in the company’s history. Like today’s deal — and yesterday’s acquisition of Admovate — much of that activity has been pure acqui-hire plays.