Publishers Weekly: A land of paradoxes, the Netherlands. Book trade concentration is little short of horrific. Depending on who you talk to, and whether Belgian Flanders is included in the calculation, two large groups of somewhat similar dimensions hold either 40% or 60% of the book market, while a third group is half as large as either of the first two. Yet it was one of the country's smallest publishers who recognized the potential of Harry Potter. Jaco Groot of De Harmonie, who buys according to his and wife Elsbeth's hunches, has followed J.K. Rowling ever since, and now has a cool million copies of the HP books in print.