My lovely daughter has in the last month read every Maximum Ride book, the month before she read every Percy Jackson book, before that 39 Clues and before that....It's always been the same for children. Hello Nancy Drew, Trixie Belden, The Baby-Sitters Club and even everyone's mate, Harry Potter.
With children it makes perfect sense to me. You don't need to waste time on all that backstory and learning who everyone is you're off on a journey with someone you know. The adventure can begin from the very beginning in Book 2 and beyond. It's adventure with security, you know what to expect and then expect a twist.
As adults though it's more perplexing that we like series and sequels so much. (I'm not immune to this I wait every year for the next Stephanie Plum novel even though I probably didn't love the last five.) Why do people want to read series set in the same small town? Or the same precinct? Of with the same lovable rogue? We certainly do and the publishing industry offers many, many examples amongst both traditional and indie authors. A series is a sure thing sales-wise assuming people like the first book and then the second. The word on the street is that if you want success write a series.
When I say I have a second book coming out the almost universal question is "Is it a sequel to Mr Right and Other Mongrels?" It isn't.
So as a reader what draws us to familiar characters and settings with such consistency? I'd really appreciate your thoughts.