Largely food and drink service, but also generally being unorganised and a bit chaotic. All adding up to a feeling that the event was not worth anything like the money paid for it.
Villa Park as a concert venue will obviously competing with other large arenas in the area which are much more established for this type of event, so real effort will be needed from the club if they see this as a permanent means of generating income
EDIT: just to add to this, one person told me that the general experience of the Springsteen gig was absolutely lightyears behind that of gigs at the Ricoh