Would love advice on book arbitrage and best practices?

You have to see how much gross profit and net profit is there in the product sale. Let's assume the net profit is X then you could ask around 15% to 20% of the net profit. It also depends on how much efforts you are doing and who is paying for the paid ads. It also depends on how much efforts client is doing to build his brand on social media and other channels because if he is doing efforts, there will be more sale of goods.

List your item against the wrong UPC code. This provided Amazon with all the correct information, including the correct photo. Then go back and mark your inventory at zero.. keep an eye on this as you don't want to sell the item as you might not have the wrong item to ship. Then email Amazon with the ASIN number and explain that you have piggybacked on the listing based on the UPC code but the detail page reflects the wrong item. Let them know that you have removed your inventory till this can be worked out. I included photos to show the UPC for the correct item. Ask Amazon to cleave the listing so you can list your item. Amazon cleaved the ASIN. I had never heard that term. What Amazon did was split the listings and assigned a new ASIN to the listing I started. This allowed both listings for one UPC code while Amazon looking into the questionable listing. You have to have a UPC code to list an item... or you need an exception from Amazon. You can't take an item that has a UPC code and add a non-UPC code item as a variation. The photos are slower than the text. When starting a new listing, the photos don't even start to be loaded until you have completed the listing. Just the way Amazon's system works.

Yes; if you do a presale, those buyers will get the book immediately upon release. Include a message in either the front or back matter that encourages them to leave a review once they finish the book. You should also encounter them to join your mailing list, that way you can continue to build a relationship with them.

Obviously you need to generate more leads. But then you need to segment your list. Your basic list are those leads who "come aboard" and want to know what's going on. Your qualified leads list are your potential buyers. Between the two, you need a gate. So, they come on your big list. Then they need to get something that qualifies them from being a basic prospect to being a qualified prospect. That puts them on the second list. Leads >> Qualifier >> Qualified Leads. What's the topic of your book? Qualify by things people have said in similar book reviews. This is a lot easier if you are doing non-fiction, but it's possible with fiction as well. In the reviews you'll see people saying things like, "I bought this book because..." What they say after that is the pain point. Use this language, as they wrote it, in your qualifier. For example, in a review for SPIN Selling, someone says, " I don't do "hit and run," one-time sales. Tom Hopkins and Zig Ziglar offer great tactics for those kind of salespeople, but they don't work for me." Another says, "...I had no idea how to sell professionally. I had already read a few books by Tom Hopkins, but felt he was targeting used-car salesmen types. It seems as though Hopkins' techniques relied on "closing" gimmicks when it came down to it. (I must say I did learn some good principles from Hopkins, but his gimmicky style is not for me.) I was instantly attracted to SPIN SELLING when I saw that (1) it was based on extensive research, and (2) it dealt primarily with the large sale. Since I want to start my own corporation after my MBA, and want to have Fortune-500 companies as my customers, I realized SPIN SELLING was for me." See the commonality? So if I was launching a solid B2B sales techniques book, I would make use of this language. First, I would attract them to my basic list with the promise of a corporate B2B sales book. Then, I would qualify further with language like, "Are you looking to build real relationships with your customers, instead of hit-and-run one-time sales tricks? Are you eager to understand the secrets of professional corporate selling?" A Call To Action would follow. Those who respond to this language are qualified leads, as salespeople in other situations would not resonate with that copy. How can you transfer what I've shown you here to your niche? If you're writing non-fiction, as I said, it should be straightforward. If it's fiction, then you can find similar stories and pull from the reviews for those...the things they say they like about the author's style (assuming yours is like theirs), the story structure, the excitement, the thought process, or whatever. Why not just go straight for the qualified leads? Because your net won't be big enough. Better to grab a whole lot of interested readers, which you can make use of later as well, and qualify from there.

First, avoid UPC codes. They're expensive + cumbersome + Amazon no longer uses them... or rather... even if you have a UPC code, you'll require replacing these with the Amazon AISN number assigned you. https://www.gs1us.org - UPC Mafia, where you purchase UPC codes. More important is a high throughput multicolor printer (to print ad-hoc labels) + a barcode reader device, to ensure your barcodes are accurate (can be read by Amazon barcode scanners).