Simultaneous substitution is a longstanding and successful CRTC cornerstone policy that helped to build — and continues to sustain — the Canadian broadcasting system.
By allowing broadcasters to temporarily replace the signal of a U.S. TV channel with that of a Canadian channel showing the same program at the same time, the policy ensures advertisers in Canada can reach Canadian audiences. It also ensures Canadian consumers are exposed to ads consistent with government directed and/or self-regulatory advertising guidelines, and that the advertising dollars generated by this policy indeed remain in Canada, to the benefit of Canadians.
RON LUND – Financial Post – February 07, 2016.