To be pretty honest, prior to my life as a data scientist (and grad school) I was a business analyst. We mined data and threw 10M-100M entries into a MySQL database w/ Rails dashboard and for our non-RT analysis purposes it was tolerable.

There are plenty of data problems out there already warehoused by small-cap and mid-cap firms; I honestly don't see a need to go Web-Scale and all that jazz for its own sake if your use case doesn't need it. There's also shortcuts like sampling to kick the can down the road, but that's another discussion in and of itself.