The decade-old podcast industry is bringing in more listeners who tune in on their mobile devices and in their cars. But advertising growth has been stymied by issues related to audience measurement and the podcast world is grappling with the same phenomenon rampant in rival media--ad-skipping, according to a report in the Wall Street Journal. "Apple, Inc., which accounts for the bulk of most podcasters’ audiences, allows listeners to skip ahead by increments of 15 seconds on its podcast application. Other podcast apps, such as Spotify AB and Stitcher, also feature a skip button. ...Podcast companies say that keeping ads entertaining remains the best way to mitigate ad-skipping. 'Repetition is what leads people to skip over and over again,' said Bryan Moffett, general manager of National Public Media, a sales subsidiary of National Public Radio that is owned in partnership with the Public Broadcasting Service and Boston public media station WGBH."