Stephen Moss, an online marketing executive with a background in print media, is the new president and c.e.o. of National Public Media, the New York-based corporate sponsorship firm representing public radio and television. He succeeds Bob Williams, who founded NPM’s predecessor company National Public Broadcasting in 1997 and served as c.e.o. after its 2007 acquisition by NPR and Boston’s WGBH. Moss joins NPM from Evri, a web technology company where he served as v.p. of business development. Previously, he was v.p. of sales for Microsoft, Inc., where he launched the MSN video service and led its rollout to major advertisers. “Steve is a collaborative and proven leader with superb talents in a highly desired space–at the intersection of media and technology–a critical ingredient to our long-term success,” said NPR President Vivian Schiller. PBS bought a 10 percent stake in NPM early this year.