iTunes capitalises on Downton Abbey popularity in US Speaking to the Television Critics Association on Monday, PBS chief Paula Kerger said putting Downton in the teeth of the competitive US autumn TV season may not serve the show or its audience. But PBS is keeping an eye on the situation and talking to stations and viewers about the issue, she said. Asked if the strong initial viewership vindicated PBS' scheduling decision, Kerger called the ratings "a beautiful thing," but added it will be interesting to see how viewership continues through the show's run. Downton Abbey is beginning production on its fourth season but Kerger refused to disclose any titbits from the new series. I'm not telling you anything about season four. Don't trick me," Kerger said. Episodes are available beginning January 29 on iTunes. The season finale airs February 17 on PBS' "Masterpiece" showcase.