Pierce The Veil on the No Gluts No Glory tour with Miss May I.
was pretty disappointing since it felt like Miss May I played for like an hour
That's quite poor coming from Pierce The Veil. The shortest headline set I've ever experience was probably 11 songs, which is still short, but not as pathetic as 8. By any chance, were there 4/5 supports on that tour?
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.