The amount you have to sell to go platinum always varies relative to population size. If every country had the same number to go platinum (1,000,000) then 1/5 of Norway's population would have to buy an album to go platinum. Canada's population is around 1/10 of the US, so selling 100,000 in Canada is like selling 1,000,000 in the US.
That makes sense. And while we're at it, 1/5 of Norway SHOULD have an Alexisonfire album.