For more than 20 years, Desiree McKenzie has been making her way to the Bourda Market three or four times a week to run her modest stall offering an assortment of books and magazines for sale. Book vending in municipal markets is an old, but less than lucrative trade. Over time, its profit margins have been cruelly undermined by the advent of electronics, though even the emergence of the Kindle has not been able to entirely displace the particular pleasure of reading the paperback.