Originally Posted by
TravellingChris
First of all, connecting in YYZ or YUL from the U.S. to Europe is not backtracking in the same way that connecting in Canada to fly to Latin America would be. Canada is directly on the flight path for many U.S. services to Europe anyway, whereas flights to Latin America are in the complete other direction. It's as illogical to fly from the U.S. to Latin America via Canada as it would be to fly from Kuwait to Dubai via Istanbul. And no, AC's fares to Latin America are not competitive with UA's or many of the U.S. carriers.
Most passengers don’t plot routes on a map or reason in terms of geographic “direction.” They choose based on total elapsed travel time, number of stops, and what booking tools surface as the best option.
“Backtracking” is a geography concept, not a booking one. If AC can offer comparable or only modestly longer elapsed times by running tight banks at YYZ/YUL and relatively streamlined connections, those itineraries remain competitive in practice. Connection quality matters as much as distance: hub congestion, terminal changes, and long minimum connect times at some U.S. hubs can easily erase any theoretical advantage from a shorter great-circle route.
That’s why this shows up in real searches. If routings via Canada weren’t time-competitive, they simply wouldn’t ranked at the top. As I have shown earlier, AC also do offer competitive pricing vs US carriers. Airline pricing is not correlated with costs of delivering the service, they will offer discounts for connections to attract passengers, hence as the previous poster mentioned, flying BOS-YUL-FCO was cheaper than YUL-FCO.