Bookswap is C2C book sharing online service for book lovers. There are hundreds of millions of books standing on private bookshelves without use meanwhile other people are looking for the same books. Publishing industry cutting trees and wasting resources to produce books which uselessly overload shelves somewhere. Estonian working prototype shows that thousands of people are willing to pay for the using of book swapping marketplace. Book swapping is classical sharing economy model which gives much more emotional touch than selling used books.