They probably gamble more than Donnie and Marie fans (and probably order more drinks).

But I think you have to think of whales as high-bankrolled foreign tourists who want the opportunity to see big international superstars. (Celine Dion "gained international recognition by winning the 1988 Eurovision Song Contest," Wikipedia points out, and has sung "in several other languages including Japanese, Italian, German, Mandarin, Spanish, and Neapolitan...")