Presale tickets are allocated by the promoter of the concert. Some tickets are sold during a presale to fanclub members, others to credit card holders. Blocks of reserved presale tickets are set aside for newsletter members, Facebook fans or even Spotify users.
A few fanclubs sell a bundle with tickets and a membership, there are some great opportunities for tickets when a fanclub bundle is offered.
While there are several ways to use a presale code, the most popular is to plug it into the box office website on the event page. Most presales seem to happen around 10:00 AM local time but this is not always the case, some begin at 9:00 AM and others have started as late as 3:00 PM in the afternoon.
When a presale password is entered tickets will “unlock” and become available after doing this and the member can purchase from that pool or block of tickets.
Different presale codes unlock different areas of the venue. Some credit cards seem to unlock poorer seats than others.