This sounds like it may be as much bad news for Starz as it is good news for Netflix. I haven't forgotten Starz' little tiff with Netflix a while back, which resulted in Starz pulling all of their content.
Maybe Starz will do okay building more and more original programming, but I've not seen anything from them that's of, say, HBO-level quality, and if they spread themselves too thin, the quality could suffer even more.
Long-term, this could be really bad for Starz. It could also be really
good, if they have some kind of brilliant plan we don't know about.