Headquartered in New York, Proclivity is the developer of a platform that provides predictive insight into online shopping and purchasing behaviour for advanced target marketing and merchandising.
WPP joins lead investor Fung Capital USA Investments and the Pilot Group as a stakeholder in the company.
WPP said that this investment continues its strategy of investing in more targeted and measurable forms of advertising and strengthening its capabilities in digital media technologies.
Last month WPP acquired a 12.82% share of IGA Limited, the Cayman Island-based parent company of InGame Ad Interactive Technology.
InGame Ad, which operates from Shanghai, is an in-game advertising network, providing advertisers with access to consumers through a portfolio of online and mobile games.