Series: Novellas in the Seven Wonders series
The Good: The background information provided by these novellas will entertain hardcore series fans. Those who want to know the beginnings of the world the series is set in will find these exactly what they're looking for.
The Bad: There really isn't enough new information in these stories to warrant them necessary to casual fans. Sadly, they aren't all that interesting either. They are very loosely related to the current storyline in the books, focusing on other characters. Novellas only really work for casual readers when they feature a well-known, beloved character.