But very frequently, it's neither of these reasons. Case in point - 100 Cupboards by N.D. Wilson. I loved that book, and my library has book two on its shelves. But did I check it out the next time I visited the library, or even the time after that? No, I didn't. One of those times, I even saw it on the shelf, yet decided not to check it out. The same thing happened with The Midnight Queen by Sylvia Izzo Hunter. As soon as I finished it, I was dying to read the next book - yet chose not to get it from the library. I read that book a year ago, and I still haven't checked out the sequel. I have a feeling the same thing will happen with The Invisible Library by Genevieve Cogman. I just finished that book, and absolutely loved it. But will I get the next book from the library when I go in a couple of weeks? Past history shows that that's unlikely.
I can't figure out why this is. So I'm curious how you read a series. Do you devour all of the books as quickly as you can get them (assuming that all of the books have been published)? Do you space them out a little bit to savor the experience? Or do you let the series hang there for months or years until you get around to finishing it, if ever?