Playing around with it, here's what I determined:
A Night Alone, currently published at $1.99 would sell more ebooks at $0.99, but I would make more profit selling it at $2.99. [For the sake of this experiment, I am going to set this ebook at $0.99 and see if I sell more as the diagram suggests.]
On the Hunt: Hyacinth and Callisto, both currently available on Amazon at $0.99 and elsewhere for free appear to use the same graph as the other books, leading me to wonder at the honesty of this tool. But, their chart suggests a 165% increase in profits if I raise the prices of these two ebooks to $2.99. [Let's try it!]
I'm interested in what effect these changes will have on my sales and profits, so for the next two months, August-September 2014, I am going to change my the prices of my ebooks to what the Pricing Support app suggests at different points along the graph and see what happens.
I am going to keep my prices the same, as they are already set, on Smashwords and all of those affiliations, for the length of this experiment. If, as a new reader, who purchased one of the books at a price higher than I have it listed anywhere else, you stumble upon this post, I apologize. You are a guinea pig. If you feel like you were cheated of money due to the discrepancy between competing sites, I am very sorry. I will offer you, as compensation, one of my other ebooks for free in your format of choice. All you have to do is send me (via email at firstname.lastname@example.org) a screen shot of your purchase order with the date the ebook was purchased and the title. I will take care of the rest.
Finally, I am a little curious to see whether or not Amazon's price checker will kick in and lower any of the ebook prices to match the other sites during the test months.
So, here's to the scientific method!