With a previous employer, I helped implement "big data" operational analytics. This wasn't just an effort for our IT team to be cool - we were seriously overworked, and we suspected we had a lot more computing capacity than we needed, and the company was hoping to cut back on some upcoming capital expenses. Implementing operational analytics isn't easy, but after a few short months it paid off: we were able to pinpoint specific areas where we had excess capacity, massively rearrange workloads, and identify the capacity we needed for new projects. Our net savings in the first two years was around $1.2M, and we'd just gotten started.