This is exactly what NNT tries to explain in Blackswan with his argument against the bell curve (in favour of Power law) a bell curve or assumed normal distribution would put 99% of the consumer base with +-2 standard deviation which is not the case in reality
it's probably just a log normal distribution, meaning that the result is a product of normal factors, not a sum. Afaik this is one of the most used models in statistics, because the central limit theorem still applies, just with sums of logged random variables instead of just sums
