See http://techcrunch.com/2011/02/11/borders/ (TechCrunch)
Borders (US company, unrelated to for instance Borders in Australia) is trading at 86 cents a share and has a market cap of USD 16 million. It has around 700 locations valuing them at less than $100,000 per store. Amazon has a market cap of about 85 billion.
I reckon there’s plenty wrong with public share trading and deriving company value from that, however in this case I think it’s quite indicative. It’s very clear that Amazon has been a huge disruptor to “brick & mortar” stores and other aspects of the book publishing industry.
Amazon allows you to browse a huge selection, and in many cases your order (at least on US mainland) can get delivered the next day. There’s also reviews, relate books/recommendations, and so on. The only thing you don’t get pre-sale is the feel of holding an actual book, but since you can browse the content online anyway not too many people seem fussed about that. I personally do love the feel of books, but I find myself mainly browsing around second hand book stores rather than those for new books.
Most likely, only book stores that occupy a niche or those that have a sane online presence will have a future. The online component will cannibalise the brick&mortar part, but depending on the setup (separate management/budget) this can coexist within a single organisation and work out alright (that is, stores may not survive but the company can transform successfully into a mainly online entity).