Like its parent university, Stanford GSB is strong in virtually everything. It is particularly known for GM, tech in its various forms, and (surprise, surprise) entrepreneurship. It is certainly not weak in finance or marketing, but probably not quite as highly regarded in these fields as some of its fellow ultra elites.
I suggest examing the Stanford Career Management Center reports for information on where students take jobs after graduation.
As a generality, the West Coast represents a majority or at least a strong pluarlity of placements. It has a higher level of geographic diversity than UCB and UCLA but less than the Top Cluster Europe schools.
Stanford's selectivity seems to be related to many factors
1. It is an outstanding institution
2. It the smallest ultra elite
3. It approaches a regional monopoly: there are no other ultra elites within 2000 or so miles, it is the only ultra elite anywhere near the Silicon Valley, and it is by far the closest ultra elite to two of the nation's five largest metros
4. Along the same lines and unlike its fellow ultra elites, Stanford's main regional competitors are public universities that have a somewhat different instituional mission.
5. It offers the best weather of the ultra elites