I have no objection or revulsion to abandoning books. If I selected books to read in a more willy-nilly fashion, I'm fairly certain I'd abandon a lot more. But as it is, my book selection process is such that a book that I dislike enough to abandon rarely gets past my filters.
The occassional clinker finds its way onto my reader, but for the most, my selection process provides books I enjoy enough to finish.
I also usually only buy books that I'm ready to read soon. Usually very, very soon. Like now.
