This tour was designed for an arena, a stadium would probably cost more due to a new stage, props and effects.

Efficiency as in Bieber's M&Gs looking like a meat processing plant?

It's the same reason why P!nk does arena dates for 600k people in Australia.

• Not making the fans queue for 3 days.
• Not making opera glasses a necessity because of the distance to the stage.
  

Katy doesn't forget the concert experience from the fan's perspective.

Really impressive!!!

So? It's not like she doesn't have the money.

But as I said this is an enormous success either way

Mas'Allah

Queen of Australia!

Get that coin, Katy!

Pink is still the unrivaled Queen

Congrats for Katy

But mess at the P!nk stan and the Monsters trying to undermine her success

slaying right and left

That's because you try to make it sound like Katy is the most successful female artist there... when we know P!nk is the queen of Australia.
But good for Katy anyway