I belonged to a book club for a couple years, finally quitting because the time of the meeting was inconvenient for me.
My opinion on book clubs: Yes, sometimes you "waste time" reading something you didn't really want to read. But I found it really opened my eyes to other lifestyles and circumstances, making me think about things I could easily avoid otherwise. I often need to have an incentive to finish things, even books. (even quilts) If I know we're going to be discussing it next week, I'll push myself a little.