is the best inexpensive product line for the German retail bookseller. Year in and year out, bustling firms sell thousands upon thousands of these little, red-and-yellow, 20-pfennig volumes. Of course, the greatest turnover is achieved by those firms that keep the complete collection in stock. Furthermore, with the Universal Library, these firms have the great advantage of constantly attracting new customers, for the friends of the Universal Library prefer to buy the other books they need in shops where they know that each and every volume of the Universal Library is immediately available. The fact that, despite these great advantages, there are still firms that stock only an insufficient selection of the Universal Library has to do, in most cases, with a lack of space. Because when displayed on ordinary shelves, the whole collection takes up approximately five square meters of wall space.