[rpeden]

You make good and fair points.

The first answer I wrote assume you've already described your unique qualities, skills, perspectives earlier in the interview. Because all of those non-monetary contributions absolutely provide value. And they definitely can be, and often are, the difference between success and failure for teams and companies.

I think if you've spent the interview gently highlighting all of the ways you provide value, then when you're hit with a closing question like "Why should I hire you?", you likely won't need to spend too much time describing what that value is. Reiterating a few of the points would often be a good idea, though.

The second, more blunt answer I wrote is probably most appropriate if you're a contractor who has to come in, deliver something valuable very quickly, and then go away.