Personally, what keeps me coming back and adding my own ideas is the continuum of characters. What the first episode accomplished that many other CYOA sites don't is that it establishes a CORE mythology that, no matter how crazy the story turns, people always refer back to. The characters, then, become familiar in some way. We're given something to work with, rather than compeltely blank slates. The main events are there too, and the good writers reference them.
THAT, to me, is the core of this series. The continuum. As long as that is kept with an establishing episode I think we will keep some of the soul.
