Case study (fiction #2)
I did a launch earlier this year and started recording my whole process. However, this was a book one for a new series; I had trouble getting reviews for it quickly (in part because it's different from what I usually write, more scifi than fantasy).
I spent big on ads for a week or two but couldn't get it to take off. In the videos, I think I already troubleshoot it a little. Right now, since it's only book one and I don't have a follow up, and since it's not selling at 99cents, I will probably raise the price to 4 or 5.99 and see if I can prop it up with AMS or Facebook ads (the higher price might let me afford to keep it more visible and appeal to KU readers... but it will still be a hard sell because it's a stand alone book. I usually let book one sit until I've got books two or three ready; I want as many reviews as possible for book one.
So while I'm working on the rest of the series, I'd either price high with ads, or make it permafree to use as a leadgen (email optins) and build reviews until the series is ready. Of course if you can write faster and finish the series, that's ideal: it's much easier to launch book one with book2 on preorder already. Since Amazon now allows one year preorders, if I was confident in my writing to a schedule ability I would just put the whole series up on preorder and then get busy finishing them (EXCEPT - you don't want to commit to a series that isn't selling, so iron out the problems on book one first; no point finishing the series if you can't move book 1 at all.
Right now I'm still using "Your next selfie: your last breath" for the hook which I've decided isn't great, it needs to hit the genre clearer. I may sneak in "litrpg" or "gamelit" because that's more the right audience, even though there's limited actual gameplay in this (I could put it in the description; I may use it in the keywords for ads but that gets dangerous if you're appealing to a popular market but your book isn't *actually* that market. Still, better to get them to start reading and figure out how to sell it, and learn from your targeting mistakes when/if you get some negative reviews (also... negative reviews are how you learn.
I just saw someone saying "I have 7 5-star reviews and am getting no sales or reads at all..." Seven 5-star reviews is about the same as having zero reviews. Nobody will trust those seven until you have at least a couple 4 stars and a 3 star. A great 1 star can even help you sell more books, or screen out the wrong readers. As long as you keep your average higher than 4.2 or so, reviews aren't going to matter that much (better to get more readers and more bad reviews than less readers and more reviews.
Also, since I'm talking about reviews - they'll be more mixed on the FIRST book because you're attracting a mixed audience. Only the people who LIKE the book will keep reading the series, so generally your second/third books in the series will have a higher rating.