Two of Boston’s best-known newspaper entities -- The Boston Globe and The Phoenix Media/Communications Group -- have launched online radio stations this year, broadcasting alternative music and featuring well-known local DJs, reports NetNewsCheck. Digital radio is unlikely a big moneymaker, said Gordon Borrell, CEO of Borrell Associates -- but audio platforms do boost online brands and create buzz among younger readers. Borrell estimates that local advertisers in the Boston DMA will spend about $424 million online this year. About $5 million of that -- about 1.2% -- will be tied to digital audio products.