will she open or close the show? which slot has bigger impact on sales?
I'm not really sure, the year of Applause/Roar I think Roar got a bigger boost despite coming at the end, there are other years when the opener has a huge effect. It depends a lot more on the performance itself. But they are the 'prestige' slots at the VMAs.
I honestly thought she would never perform on an award show again, let alone the VMAs Regardless of how I feel about the music she's been putting out this year, this will be a big moment.