My latest book (still no reviews and low price) got 3 sales via ads yesterday (Thursday). Interesting is, that one sale of two copies happened with a brand new keyword that I never thought possible to trigger a book sale (proof: 1 impression, 1 click, 1 sales).
The hardcover also seems to have gotten a sale. It has a real BSR this morning.
Probably due to the HC, the book is #1 again in New Releases of its main category and #5 in an associated gift-book category.
Wishing you all a lot of success - Friday Flourishes