A pointed, but useful, interview question
Dan Sweet poses a hard-hitting interview question in Hiring outside talent: a good culture indicator:
One of the best interview questions that I know of is, “Why aren’t you filling this position internally?” Almost NOBODY asks this, but it reveals a LOT about the company.
I don't think I'd ask it that directly if I wanted the job, but it's a thought-provoking question that you might want to get at indirectly. It gets at the internal dynamics of the company in a way that you would want to know before joining them.
My personal favorite is, "What concerns do you have about me in this position?" It invites the interviewer to bring up unspoken objections so you can deal with them.