Jimmy Kimmel will be Stephen Colbert’s The Late Show guest tomorrow night, part of the great circle of mutual back-scratching that is late-night TV these days. Kimmel’s following the path to Colbert’s Ed Sullivan Theater already beaten by NBC’s Tonight Show host Jimmy Fallon and Comedy Central’s new The Daily Show host Trevor Noah.

Why now? Kimmel’s appearance will bring eyeballs to CBS while his own ABC show is airing a repeat. He’s looking to plug his show’s return visit to Brooklyn, a trip Jimmy Kimmel Live! first made in fall of 2012 when David Letterman was Kimmel’s guest.

Meanwhile, should Kimmel, while goosing Colbert’s Friday ratings, convince some of those viewers to watch Kimmel’s ABC show all next week, it’s no skin off Colbert’s nose – The Late Show is in repeats all next week.

Tonight Show Starring Jimmy Fallon logoKimmel’s guest spot on Late Show comes as final stats come out for Colbert’s third week hosting. They show Colbert leading Kimmel in the demo (0.64/3 to 0.53/3, respectively) and in overall audience (2.9M to 2.2M, respectively). NBC’s Tonight Show Starring Jimmy Fallon topped both shows with 3.5M total viewers and a 0.88/4 in the demo. Fallon equaled his biggest total-viewer margin to date (22%) versus Colbert.

With these stats factored in, Colbert’s season-to-date 3.4M viewers tops Kimmel’s 2.4M. And Colbert’s demo rating of 0.82/4 bests Kimmel’s 0.57/3. Here too, NBC host Fallon leads the way, with an average of 3.8M viewers and a 1.04/5 demo rating.