There's definitively a value in knowing about culture, and being able to categorize it and discuss it on many levels. If you simply want to get through to more people, the most direct approach I can think of is to study things like rhetoric or take communication classes. There's a wealth of knowledge there for how to improve the way your communication impacts and includes other people. And while I'm at it, let's not forget the cross-section between marketing and psychology, for all those boiler-room types among you. :D