The end of the 'Late Show' franchise is a major blow for a once-beloved TV format, which has lost relevance and advertising dollars.

It's difficult not to see how an ownership change impacted 'The Late Show' franchise, but the move also reveals stubborn truths about the cost of the programming vs. cheaper and infinite YouTube rivals.

With the hosts Merv Griffin, Pat Sajak, David Letterman and Stephen Colbert, CBS has taken many runs at late-night TV. Some were more successful than others.