You often don't know who is calling you until you pick up the phone, so you can't make a judgement about whether it's worth paying for the call until you've alr

You often don't know who is calling you until you pick up the phone, so you can't make a judgement about whether it's worth paying for the call until you've already started paying. That, combined with the fact that it appears to be unique to just the US & Canada (maybe NANP in general), makes it bizarre to me.