It used to be easier
Oh, for the halcyon days of 2012 and 2013, when your book going up on Amazon attracted eyes, especially since the categories weren't any too large.
I still have my souvenir of being #1 in a niche category. 
It spoiled us for a while. We wrote as quickly as we could hoping to outrun the “tsunami of… stuff” rising up behind us. Some of us are still trying that as our primary method of coping.
I'd like to present some more sobering numbers.