Why I Simultaneously Hate and Somewhat Appreciate "Filler Books"

If you have read any book series in your life, chances are you have read what we call a "filler book," or a book that holds not enough significant information to merit over 50 pages. A book whose only true purpose is to continue building tension between the protagonist and antagonist and leave you with a severely annoying cliff-hanger and a year to wait for the next book. And yet we find ourselves reading these and anxiously waiting for the next installment in the series.

You usually can't tell your reading a filler book until you've finished it. And how do you know you've read a filler book? Because you feel like you haven't actually moved forward in the story. Maybe you've gained a tad bit more information, that isn't all that important to the overarching story. Most of the time, when you finish the book, you feel no sense of accomplishment, and find yourself saying, "That's it?" or "I just spent $20 to buy this is hardcover?"

This is why I despise filler books.

I would be lying however, if I said that I didn't also somewhat appreciate them. (This statement depends completely on whether or not the preceding books were worth reading).

Usually (again depending on the series), when I read a series, I get severely attached to the characters. They become my best-friends, and I don't want to grow apart. (Only a slight exaggeration).

I read the Maximum Ride series... when I thought it was just going to be three books (It's finally going to end in August 2012, 5 books and 3 comics later). When I found out a fourth book was in the works, my heart fluttered a little. And then I read the book, and then I read the book after that, and the one after that etc. etc, each time hoping that something would happen. I was slightly relieved by Angel, but still waiting for all the pieces to [hopefully] come together in the end. Filler books drive me crazy, but when you fall in love with characters, you don't care as much when they run around doing nothing.

When an amazing series ends, I can't help but silently demand more from the author. The Harry Potter series comes to mind. As much as I disliked Harry Potter and the Order of the Phoenix, and am convinced the only reason for that book was to kill Sirius and give us a real reason to hate Voldemort, I am glad that Rowling let us live in the Wizarding World a little longer.

But for me to even consider somewhat appreciating a filler book, it better be a dang good series.

What series have you read with a filler that drives you crazy?