What is Gamification, Really?

That's a great point about the parallel development of games and story telling. It's also a good reminder that when we think about games and gamification, there is a deep history to draw from that predates digital games.

On the implementation side, one way to think about it as a gamification designer might be the primary set of tools (e.g. core game mechanics, player objectives, end states, etc.) and then secondary game related elements that latch into your system. As with your example around narrative, secondary gamification design tools might provide opportunities to customize the play experience, or they might be approaches for creating tight coupling between other aspects of the system you're tweaking and the game layer (e.g. the reward system is meaningful in relation to the game layer).

While this more nuanced approach might be less essential in explaining the work to a client (or potentially confusing depending on their background), it offers the designer a mechanism for focusing on the roles of different types of game and game related attributes in their design effort.