Why, here's a helpful illustration, from Live Nation's own literature!
What it means: At the time this chart was done, approximately 2007, Live Nation merely controlled the three black arrows in the middle. If the merger with Ticketmaster goes through, it will control every aspect of the business between the artist and the fan, except for the booking agent.
However, given that Ticktemaster/Live Nation also would manage artists -- like Madonna, depicted here long before she signed her 360 deal with Live Nation -- the booking agent would become extinct soon enough. Why would the company, in its role as manager, want to hire an agent to negotiate with the company, in its role as promoter and ticket-seller?
Artist Nation. Live Nation. Fan Nation... Abomination?