Sign of a good bookshop

What are the signs of a good bookshop? Location I guess comes into it but it’s all about what is inside. Ambience, feeling an aura of mutual literary respect are great but the finishing must is the selection of books.

Having trawled round various bookshops in search of Blood Meridian by Cormac McCarthy, which I have been told is bloody but good. It was only in Heffers on my day trip to Cambridge that I came across such a comprehensive collection of McCarthy that I was able to get my hands on the book.

A sign of a good bookshop has to be the range of choice, and not just mainstream titles, with that in mind Heffers came up trumps today.