TORONTO - National radio sales fell 1.2% in Q1, according to information supplied by Canadian Broadcast Sales (CBS).“September, October and November were difficult months in the world economy and that uncertainty was beginning to be reflected in radio’s results, as it was for all media,” said Patrick Grierson, president of CBS, in a press release. “Interestingly, our year-over-year churn in Q1 was constant. In any given quarter approximately 40% of advertisers from the previous year do not repeat or spend less on their campaigns, but we traditionally replace that advertising and bring in new business. For only the second time...