They wouldn't be as big as us but they are a massive club. People saying they aren't I think are being obtuse
They arent a massive club though, they benefit of pockets of overseas support from mainly America, thanks largely to the irish connection. As far as i can tell, they dont have a large following in places like the middle east, asia, oceana, south america, and if they have, they've hid it very well. They play a friendly in Boston or New York and fill a stadium, but they wouldnt do that in Manilla, Jakarta, or Melbourne. They struggle to fill that stadium every week, and to use modern parameters as much as it pains me to do, they have less twitter followers than Valencia, Sunderland, and Lyon.
Their whole season was based on 4 Old Firm games, and an annually shite European campaign, and after Rangers were relegated, most of those who were interested, weren't anymore,