system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does event ticketing work, i.e., What economic principles allow Ticketmaster to charge such high fees for such an easy task?

Some questions I have are: Are venues obliged to use Ticketmaster, and if so, why?  Why aren't their fees considered an abuse of monopoly power?  What are the fees even for?  Why are bands and/or venues willing to allow a middleman to screw consumers so badly?  Are there any alternatives to the current system?  Are there competitors?  Who has the power to NOT use Ticketmaster (how could it be accomplished)?
gpt
Basically, ticket master takes the fall. 

Ticketmaster makes 4% of the total price of each ticket. The fees and all don't actually go to ticketmaster, instead, ticketmaster takes the blame and passes most of the earnings onto the venue.