Dropping this in, in case I'm not too late! Lora Nox and I have a mafia series (4 books with at least 2 more to come) and an MC series (2 currently out with more to come). These are all interconnected standalone books and series, weaving together to create a "universe" (I have more series planned). Note for the mafia series (the 1st books are about the three brothers), and about the book Tommaso: I never planned to write this book about the parents' story, and I made it the prequel due to the timeline (and I didn't think it made sense to label it book 4 since it jumped back in the timeline). It's currently my reader magnet for getting newsletter subscribers, but I plan to write a new reader magnet (more of a novella rather than a full novel) and move Tommaso into KU. I'm not sure if I should keep it labeled as a Prequel, though, or how to position it within the series.