I know we're all struggling to sell our books, but summer is usually worse than other times. With everybody heading someplace for recreation, most people don't bother to look at books by unknown authors. The last few years I had no sales to speak of during the summer.
This year, I stumbled over a guy called Nick Stephenson and (reluctantly) signed up for his free video training. Since I already owned KindleSpy (a program I used to track rankings and sales of several books I'm using to compare to mine), I applied his advice to my fairy tale books a little more than a week ago. And believe it or not, I've already sold more books in that week then what I sold last summer in total.
I'm most definitely going to adjust the keywords of all my published stories (Sometimes I dream of having more time).
I wish you a wonderful summer,