Most concerts have VIP or early bird tickets, where the front sections are open only to people who have an account or something similar on the band's website. A couple weeks after, ticketing is open to the public.
A good example of this is when I saw Rush at the state fair, all of the floor seats were VIP only (members of the Rush fan club or whatever), the grandstand was open to the public. Needless to say, it was sold out.
