Good luck with your promo.
I've never been able to get a BookBub, even with Muted that now has 184 reviews/ratings and 89% of them are five-star. They don't want any of my books, even free.
I did a free promotion this weekend with Star Writer (romance, women's fiction) if anyone's interested in comparing results. Sales were only a few a week, so I may as well give it away. I've almost always covered costs of promos in the past from read-throughs even though the books are stand-alones and not a series, so fingers crossed that happens again.
I dumped most of the promotions onto the second day to try and jump into the top 100 overall free.
On November 19 it went free and I just did some posts in Facebook groups for 75 downloads.
On November 20, I had Free Booksy, Fussy Librarian, and Book Doggy, and had 3,305 downloads which put the book into #35 position in the free lists (overall), with positions 1, 4, and 10 in some big categories like Contemporary Romance.
November 21, no paid promotions but getting up in the ranking fuelled downloads and there were 1,180 and remained in the low 40s overall-in-store most of the day. Staying on that first page of 50 books in the Top 100 certainly helps.
November 22, I have a Book Cave and Fiverr BKnights just to try and stop the ranking dropping like a rock. It's already back down to #62 overall in store (free) and 1, 6, and 18 in categories, so it's about to be goodnight from me.
I've found this pattern of promotions has worked well in the past - if you can get seen in the first rows of categories or first page of overall, it definitely drives downloads. Hopefully, some of the downloaders actually read the book, like it, and see the message at the end, 'If you enjoyed this, you might like Muted - with 184 reviews and 89% of them five-star, it's proving popular with readers.'