reviews on the tickets sites, yelp, etc. A show can sell out and "do well" with people leaving disappointed. I'm pretty sure if he had those reviews and a potential 6-month contract, WOM would've put a dent on the second half of the run. But I'd dont see the show so maybe people were just overly critical
And I've been to outkast concerts and the festivals they've played at, that mashup shyt ain't nothing new, a bunch of hipsters who think they're on because they know some iconic rap groups mushed in with alt or EDM...ok. No 45 year old white women are coming to see dre, retirees who frequent Vegas ain't seeing him (my parents and their friends -60+ - try to stay hip, i guarantee they know ms Jackson and hey ya....on the other hand, I've seen about 6-7 of them OWN cee-lo's album), no Asian business men, etc - they will see Britney tho, she's a name like gaga or Madonna and she's a performer.
Young folks don't do shows like that in Vegas, and not the crowd who rushes to see kast at festivals. And, it's not like he made much music solo, he won't be doing anything pre stankonia, idlewild was weak sauce so that gives him the hits from stankonia and love below. Dre could easily sell out a month shows (depending on venue size and promotion), I give you that, but he's not billing no 150 dates tho.
Give me the set list you think he could do for 90-minutes dolo, a set that appeals to young and old fans as you say. Britney, is in a 4500 seat theater, so 90-minutes, 150 shows, 4500 people...what does dre have for this? At 4000 ppl per show, 150 nights that's 600k folks he needs to bring to Vegas...you think he, alone, can pull 600k folks to come see him?
there will be in Vegas...plus the show got mediocre reviews, guess his new white fans weren't a fan of his Goodie Mob set 
for anyone's money.
