They can do that because they’ve written a lot of buggy code and then gained experience fixing it. This book captures all this experience—use it, and you’ll find you write fewer bugs, and the ones you do write will become easier to hunt down.
Along with the issue you will also periodically receive offers, tips, and other exclusives from the Pragmatic Bookshelf that you won't gain elsewhere.
The Pragmatic Programmers is a company with a simple goal: they want to improve the lives of developers. They do this by creating timely, practical books, audio books and videos through the Pragmatic Bookshelf and working closely with the Pragmatic Studio to create the best developer training there is. The stuff they produce is timely and relevant because it is written by programmers for programmers.