What is exactly the golden circle?

Marijke is right. The size of the GC depends on the size of the venue and the law in the country. It is not there to sell tickets but for security reasons. I don't know, maybe the UK don't have a law about security barricades at concerts but most European countries have it meanwhile after a few people died during concerts.

Uumm i don't know....There is no law concerning it in the Uk...for example Oasis played at the City of manchester stadium last year and ther was no front pit...and there is one for the Bon Jovi show this year so its clearly to make money really in the Uk's case....the promoters proberly think its a good idea to do and it makes the crowd more managable etc... but i think its their for the money lots in this case...