THE PLAID AGENCY in Indianapolis has hired Eddy Gilfilen as campaign manager and Mary Welch as copywriter. Gilfilen has served in notable roles for High Return Real Estate, VEGA Americas, and Tier1 Performance Solutions. He earned his bachelor of business administration in marketing and information systems from the University of Cincinnati.  Welch recently served as marketing communications manager for Phi Kappa Psi Fraternity. She earned her undergraduate degree from the Indiana University School of Journalism.