Adding yet another overseas string to its bow, advertising group WPP’s WPP Digital division is buying a minority stake in Chinese rich media ad delivery outfit HDT Holdings Technologies. HDT makes iCast web ad serving software, iStreaming video ad server, contextual ad delivery software iFocus and the T2C ad network, which claims over 200,000 publisher sites. The stated rationale for the investment - once again: “developing its services in fast-growing markets and sectors and strengthening its capabilities in digital media”. WPP joins existing backers CA-JAIC China Internet Fund, Cheng Wei Ventures, Manitou Ventures and Sequoia. HDT employs over 270 at offices in Shanghai, Beijing and GuangZhou. Release.

WPP recently invested in ad-friendly game maker Realtime Worlds, ad targeter Invidi, engagement metrics firm NuConomy, ad tracker IMMI, VideoEgg, Visible Technologies and Spot Runner. Its Wunderman marketing services unit acquired Chinese online ad network Agenda in January and Canada’s Blast Radius in October. Not forgetting the $649 million 24/7 RealMedia acquisition last year and many others.

• WPP Amongst $50 Million Investors In Game Maker Realtime Worlds
• WPP’s Wunderman Buys Chinese Digital Ad Network Agenda
• WPP Takes Stake In Engagement Metrics Firm NuConomy