So the question is…when do you sample and when do you not?  And does it even matter anymore in the world of big data?   As I’ll lay out here, in most cases today there is no point in wasting energy worrying about it.  As long as a few basic criteria are met, do whatever you prefer. First, let’s take care of the cases where sampling just won’t work.  If you need to find the top 100 spending custo…