Not sure I ever got a screen shot or noted my Amazon author rank numbers during my first year as a published author, but before it rolls off the chart, here's my second and much of my third:
It fluctuates a lot—do not base your self esteem on this number—but it's clear that having two books out helps a lot. It'll be very interesting to see what happens when I add a third to the mix, which I hope to do next year.
I suspect that the few dramatic drops in 2014 (one of which was on my birthday, which I find rather uncivil) relate not so much to my books' performance, but rather to dramatically good performance of one or more other books in their category. That July downturn correlates well to a lot of social media chatter, for instance, about Jeffrey Morgenthaler's Bar Book, and I'm guessing many purchases of that excellent tome.