I'm watching Better Call Saul after binging Breaking Bad... How did the studio know Bob Odenkirk could carry a series himself? How do studios work this kind of thing out?

I'm just thinking that some actors and characters excel as secondary supporting cast, but what is it about a character / actor that would make a studio think "hell yeah, this has legs?"

I'm not specifically talking about Better Call Saul and Breaking Bad either... Which I am loving, I just mean generally.

As a counter, for those of​ you old enough, why did the Friends spin off Joey fail?