I am really going out on a ledge here but obviously "so what" here is not exactly the "so what?" when used in colloquial language... So the way I understand the question is "does it really give you the essential knowledge?" The following sentence in the source text supports this idea: "What is the one most important thing [...] needs to know about [...] and why you are working it?"
As such, seeing as how the source text chooses a rather "colloquial" term, my suggestion would be "das gewisse Etwas" the "je ne sais quoi", that what you really need to know about the account that can't necessarily be found in any formal analysis... something between the lines kind of idea...

English term (edited): so what

Context
Does your SWOT really tell you the ‘so what’ about the account?

Ergibt Ihre SWOT-Analyse wirklich ein aussagekräftiges Gesamtbild des Kunden?

“so what” ist hier in Zusammenhang mit dem davor stehenden „SWOT“ zu sehen, d. h. es ist die Folgerung / das Fazit aus der SWOT-Analyse. Die SWOT-Analyse ermittelt „strengths“ (Stärken), „weaknesses“ (Schwächen), „opportunities“ (Chancen) und „threats“ (Gefahren), ergo: ein „aussagekräftiges Gesamtbild“.