I know I may get some comments on how wrong I am. Still, I know I am not a fan of reading them and I wouldn’t use them. They had their place for world building or setting up a dramatic arc, but I think there are more interesting ways for a writer to achieve this.
Personally I am a big fan of the flashback and extended flashback. Recently I read Timothy Zahn’s Thrawn Alliances, his second book in the Star Wars Trawn trilogy of books. The story had to unfold in the past and present of the two main characters in the book. The author wove both stories together jumping from past to present roughly every other chapter. As a reader it took a little to get into the rhythm of this but it proved to be a very effective way of dealing with the story arc.
I often use and like when dialog is used to bring out characters’ past connections and or conflict. The key in any great book is conflict. How effective the author is at setting up that conflict no matter what, when, or how it arises is the difference between a finished book and a pass from me as a reader. Too often prologues hit me with a, “might as well read this first because it’s gonna be part of the story later.” I’d rather get to the story right on page one.