When I see people reading, the first reaction I have is a little spark of joy that someone is reading. The bigger the book, the bigger the spark. Then I try to catch a look at the spine, to see what they're reading. It's like catching a glimpse into the person that they really are. And yes, I am a person who secretly (not so secretly anymore) enjoys reading the Kitty the Werewolf novels. I can't help judging the people who read the books I don't like, though. I'm impressed by the people that tackle James Joyce, but when I see someone reading Twilight, I want to rip the book out of their hands and give them something better to read.
Beyond my personal judging about this, it also gives me kind of an ethical quandary. This doesn't come up that often, but when the money at the library starts to run low I have to decide what to by. It often comes down to a battle between the good books and the fun books. Should I buy the books that "should" be in the collection? The literary award winners? What if I'm pretty sure that they'll just sit on the shelf for months, or years, without being checked out? Or should I buy the fun books that I know won't just gather dust? In the end, I usually buy a mix of both. I know that when visitors come to my library, they're judging us a little by what's on our shelves. So I want them to see that we have the Booker Award winners and The Walking Dead graphic novel series.