Jill Yablon, former vice president of content and new business at Greenhouse Networks, has been appointed vp, marketing at BarnesandNoble.com, New York . . . Magnet Interactive Communications, Washington, D.C., has named Christopher Wuhrer director, media planning and online marketing. He had been ad manager at Intuit, Mountain View, Calif. . . . Matthew Tucker has been named director, Internet sales and marketing at Reed Elsevier's ECM group. He was online development director at Cahners Business Newspapers Group, both New York . . . At Atlantic Records, Karen Colamussi has been promoted to senior vp, general manager of new media and associated labels.