Enrolling a title in KDP Select makes Amazon the only place the ebook may be sold, and your own shop is one of the places that forbids. So the first question is not which storefront to use. It is which of your titles are enrolled, and whether the page reads they earn are worth more than the readers you would own. For a lot of authors the answer is that some titles are and some are not — which is allowed, and is what most of this market already does.
Often no, and this is the wrong product for you if the answer is no. The test is what share of a title's income arrives as page reads: if borrows are most of it, exclusivity is paying you and a direct shop is a distraction from a working business. Two things make the decision smaller than it sounds. Select is per title and runs in 90-day terms, so it is not one switch for a whole catalogue — turn off auto-renewal on the titles you want back and they are yours at the end of the term. And going wide does not mean leaving Amazon: the book stays on sale there, it simply stops being the only place. Most authors who sell direct arrived here by moving a backlist first and leaving the earners where they were.
A mixed catalogue is the normal case rather than a compromise — roughly a third of indie authors have everything in Select, a third have nothing in it, and the rest are somewhere in between. Book one can stay enrolled and earning borrows while the rest of the series sells from your own shop.
The titles to take out are the ones earning least in page reads: older books, box sets, the first series you wrote. They are also the ones your list already owns and would buy direct from you, which is the whole reason to have the shop.
No listing fee, no contract, no territory. Sell the same file on Amazon, Kobo, Apple and your own shop on the same afternoon, and stop any of them without telling us.
The free tier runs to $500 of sales a month with no card on file. Put one out-of-Select title in a shop, send it to your list, and you have measured whether your readers buy direct — which is the number the whole decision turns on and nobody else can tell you.
Your pen name, your bio, and every book in reading order in one place. One link in the back matter instead of a different one per title, so a reader who finishes book three finds book four without going anywhere.
Every direct sale hands you the buyer's email address. That is the thing exclusivity cannot pay you in, and the reason a wide catalogue and a list are worth more together than either is alone.
Nothing changes about how the book is made. Vellum, Atticus, Sigil, Reedsy, a designer's file — the same EPUB you send to KDP is the file that goes here, checked against the spec on upload.