[HodGreeley]

I think I can give one concrete example where a NoSQL choice (often) makes sense. Common modern day scenario in mobile is to build an app and iterate. Migration in RDBMS rapidly becomes a real pain. Worse, you have no good sync solution in case you need it. Contrast with something like Couchbase Mobile. NoSQL embedded db is much easier to get going with. (Just check the Android docs on using SQLite and see how it compares to "here's my JSON, done".) Sync doesn't get in the way, but if/when you need it, you're going to be really happy it's there. (Disclosure: I work for Couchbase.)