> but I am sure people have a choice

Often, they do not. The DOJ is currently suing TicketMaster because they have exclusive agreements with nearly all of the large venues and that prevents those venues from using other ticket providers. To be fair to TicketMaster, they argue they are not a monopoly because there are many smaller venues that they are not exclusive with.

But, TicketMaster even requires that artists use TicketMaster's promotional agency if they want access to these large venues.

And more evil stuff! Details here...

https://www.justice.gov/opa/pr/justice-department-sues-live-...