I've found my self in this position as well.

So far I've managed to identify a few key points which has served me well so far.

- Being able to produce results even when there is a lot of unknowns.

- Fairly good communication skills across several departments. People usually listens to what you say.

- Being known as goto kind of person. If it's about getting the gist about something or direct help of implementing any kind of service/api.

And lastly the main point of being Sellable: Being a generalist has put you into a lot of scenarios were others have no previous knowledge about. And thus making you easier to act as an early asset in assignments.