NEW YORK--One of the masterminds of Barack Obama's groundbreaking online campaign model has joined Burson-Marsteller as chief strategy officer in the US.

Thomas Gensemer is departing Blue State Digital (BSD) after seven years as managing partner and CEO of the digital agency, which was acquired at the end of 2012 by Burson parent WPP.

At Burson, he will report to US CEO Dave Denherder, taking on the chief strategy officer role that was previously occupied by Don Baer, who became global CEO of the firm after the departure of Mark Penn to Microsoft last year. 

According to a statement, Gensemer will "focus on developing integrated client campaigns, new product offerings and thought leadership strategies for the firm."

During Gensemer's tenure at Blue State Digital, the firm played a pivotal role in President Obama's successful online fundraising and social networking campaign during two election bids. The firm's work helped to reshape traditional notions of digital marketing, and saw Blue State Digital expand its work beyond politics into NGO and corporate clients.

Prior to joining BSD, Gensemer served as digital director for America Coming Together and worked on the launch of luxury brand KikiDM. From 1999 to 2003, he served as a director of VC fund the Accelerator Group.