They've figured out that people attending these events aren't going to take anybody's broadcast revenues by sharing on social media. It's about sharing the experience with their friends and family. A picture, or video clip, that shows...I was here!! This helps build up the hype, viewership, and attendance overall.
I personally prefer Hangouts. It runs on all platforms and seems pretty close on all.
"Gotcha, you snot-necked weenies!" -- Post Bros. Comics