The key takeaway from all I've seen is it's not just telling stories, but like some of the more recent pre-literacy Western oral traditions, is more like a formal passing on, testing, repeating to ensure the message is passed on accurately.
I was just reading about a culture that passed on knowledge orally by listening to important people on their deathbed. This was unfortunate in the context of the 1918 flu epidemic.
I believe there was at least one plains indian tribe that banned any discussion of their historic stories unless there were at least a dozen members present.
