I'm not a page OR a librarian, and as such I am a bitter and marginalized Unshelved fan. Okay, so not really. The series is hysterical to me partially because I DO work at a library, and know how much of it is true, and partially because it's hysterical. Doreen is badass.
Also, yes, I have yet to find a library employee who hasn't heard of it.
Also, the repetition deal? Maybe. I haven't noticed it, though the reviewer above me did have an example, the second one had something to do with an error in the archive, I think. There might be a case for repetition, but on the whole it's original and entertaining.
Though I occasionally feel the need to describe it as "Dilbert in a library