* Gary M. Mulloy was named CEO of Windsor, Connecticut-based ADVO Inc., from president and COO. Robert Kamerschen, who has held the CEO title since 1989, continues as chairman. Mulloy will retain the president's title.
* Mike Phillips has joined Yankelovich Partners, Norwalk, Connecticut, as vice president, database marketing, a new division for the company. He was formerly a senior manager in KPMG's ICE practice, managing analysis, data mining, and database marketing.
* Mary E. Kohlhase has been named president of Media Resources International, New York, a provider of barter services to major corporations. Previously, she was executive vice president, director of account and media services.
* Former president of Nabisco Brands USA, Peter Rogers, has been named to the new title of chairman for Relationship Marketing Group, a Fairfield, Connecticut-based data mining and database marketing company. Most recently he headed his own corporate consultancy.
* Robert D. Griffith has joined the Radio Advertising Bureau as senior vice president/station, West Coast office. A veteran in the broadcast industry, he will be based in the Los Angeles office.
* MarketSwitch, based in Herndon, Virginia, has hired Dan Twomey as senior vice president of sales, and Mark Ahrens as vice president of marketing and product management. Twomey has held several business development positions, and Ahrens was worldwide alliance manager for IBM's campaign management product, ValEX.
* Susan Ward has been named general manager of the Langhorne, Pennsylvania, office of Harte-Hanks Response Management, San Antonio, Texas. Most recently she was telemarketing campaign management support at Princeton Management Resources, Princeton, New Jersey.