The OP asked for it and gets the honest answer.
I bought a festival ticket to see Halsey and got Rih for free. I asked around in the center of Europe and first response was "Never again!":
- She was late.
- Security threatened the audience that everyone has to sit down in their seat or she won't be coming on stage.
- She strolled half assed on stage like she would rather be somewhere else.
- She doesn't sing much of her songs.
- She has an air of arrogance like you should be happy that she is only 2 hours late and not 3.
We all saw those newspapers dragging Rih:
http://atrl.net/forums/showthread.php?t=1043278
It's actually a wonder that there are still people wanting to buy her tickets. Well, you can trick a naive customer once and he/she will be totally convinced to never ever go back to her. Considering that there are new people born every year and her hits recruit people every year, there are always yearly new waves of naive people. What an unsustainable business plan, somehow she can pull that off.
The reason why a Katy tour, a Taylor tour,... did better is because they gave their audience the positive experience and convinced them to go to their next tour.