Bluefin Labs announced that former Nielsen executive Scott Grunther will join the team as senior vice president and general manager of media products. In this new role, Grunther will work closely with TV networks to help them leverage social TV insights from Bluefin Labs to drive ad sales and strategic programming decisions. In addition, Grunther will direct the business and product development efforts for the company’s media clients. (Release)

Daniel L. Knotts has been named chief operating office of R. R. Donnelley & Sons. Knotts, who has been at the company since 1986 working in a variety of roles, most recently as group president, is succeeding John R. Paloian, who is retiring. Paloian was at Donnelley for over five years. (Publishers Weekly)

Japanese advertising/PR firm Dentsu announced plans to acquire independent PR firm Mitchell Communications Group. Dentsu Inc. senior VP Tim Andree told Ad Age that the company wanted to expand its ability to serve clients that “have been asking for PR and strategic communications and capabilities”. Over the past few years, Dentsu has sought to meet this need and expand its Dentsu America group by purchasing several independent shops outside the Asia market. Mitchell is an Arkansas-based firm that has handled such big-name clients as Walmart, Tyson, P&G, Sam’s Club and Hilton Hotels. Mitchell CEO and founder Elise Mitchell will be responsible for identifying other potential clients for the newly expanded firm. (Ad Age)