Kindle Unlimited Reads discussion

Hello! How long books do you prefer to read? Would you start reading/be interested in a 600 page book by a new self-published author on Amazon? Or would you prefer to read it in two parts - the book being split in two and sold as such.

I've read that breaking it into 2 (or even 3, if the breaks are natural) parts is good since readers invest not only money but also their time.