This year I’ve been visiting a lot  of bookshops to organise readings/signings for my novel and I’ve found each as fearful and defeated as the next in their efforts to ward off extinction. They are fast becoming as quaint as loose-leaf tea leaves in china pots, but it wasn't until I was standing in Union Square, San Francisco, looking up at the big, empty, boarded-up building that used to be Borders, that I realised we were way past the turning point of…