First of all: Welcome to Steemit!
About the influence into a post, I wouldn't know exactly how to answer to that since I'm not into the numbers and all the research I did makes contradiction between each other.
What I know is that the fluctuations in the price of the steemit currencies make the whole impact (in terms of dollars or money our posts say they earned) we have into others.
But still, thanks for the info, its been a bit tough navigating the website, but its little bits of information that help out a lot in the long run :)