Get up and running and making money as fast as possible without being too stupid. This might mean using a NoSQL database. MongoDB seems easy to try out, it co

Get up and running and making money as fast as possible without being too stupid. This might mean using a NoSQL database. MongoDB seems easy to try out, it could be something you'd use for some component. But most projects fail before they ever reach some minimally useful state, not because they don't scale. Plan ahead for scaling where appropriate, but the main focus should be getting it out there in a useful state.