My sister and brother in law had a neilson box and htey watched Conan and Craig, switching here and there, then Conan and Craig when Conan went to the Tonight Show. So, yes, white people watching Conan.
And if there is a difference in how the fanbases watch the shows, thats more a statement on the businesses being behind on advertising. If things are moving to more net based watching, whats the point of sticking to an older TV audience that is dying out? It's ignoring the trend and another example of businesses not wanting to move with the advance of consumer bases.