On the subject of Donny & Marie
, I have the following stats courtesy of Pollstar's EOY North American charts (I can find no Billboard boxscore or Pollstar data for 2013 or before):
2014 - 49,418 tickets | 94 shows | $8.3m
2015 - 54,472 tickets | 95 shows | $6.7m
2016 - 52,083 tickets | 88 shows | $7.5m
2017 - 53,494 tickets | 93 shows | $8.1m
= 209,467 tickets | 370 shows | $30.6m
The residency started in September 2008, originally for 6 weeks, and it's always played at the same venue (though that venue was modernised, revamped and renamed in 2013). According to this article
, they'd played nearly 1,200 shows by November 2015. If that figure is true and their ticket sales are similar to 2014-2017, they are a certified $100m+ Vegas act.
Contractually, Donny & Marie each are reportedly paid a base salary of $1.6 million per year + 40% of the ticket sales once the value of those ticket sales have topped $250,000 (now, I'm not sure what that $250,000 relates to - it could be a weekly figure, i.e. if the pair do ticket sales of $300k in one of their weeks, they get a bonus of 40% of $50k).