The design is pretty unique, I for one have never come across a shop that is entirely filled with stairs. I love the idea, the shop wont be able to house a huge collection of books but what it will offer is an extremely enjoyable browsing and reading space.
The bookshop will not only act as a retail space but will also be used for events. The social dynamic of the room will be unusual, with everyone on different levels and even people at the back of the room visible from outside the shop. The outward looking nature of the shop is an unusual characteristic that I like but at the same time could be a distraction for those wanting to read or leave people feeling on show.