M
Mario500
Guest
What seems to be getting lost in all this discussion of Rivers' Late Show in the '80s is that it was intended as a vehicle to attract younger stars (and thus, younger viewers) to late-night TV. Whether this was successful is open for debate. There was some concern that anyone who appeared on the Late Show would be blacklisted from also appearing on Tonight, but it seems to me that NBC didn't even want the type of stars who would have appeared on the Late Show, whether they actually appeared there or not.
As for Joan, the failure of this particular show was one of only a very few (albeit a very high profile one) in an otherwise very successful career. She had a talk show in the '60s (That Show or something like that) that only lasted one season. (Maybe she should have avoided shows with very bland names!) But her daytime talk show (I never saw it) lasted for years, and of course, her deal with QVC lasted many many years.
According to the Internet Movie Database and Amazon, "That Show" (you were correct about its title) was a daytime program just like her other talk program ("The Joan Rivers Show").