This book is for people who have clients, managers, and co-workers always asking them for more. It's a book for people who need to write better web applications faster. My guess is that includes most of you.
Your boss, your customers, your co-workers want more software than you can write, and they want it now. On the other hand, you have enough trouble trying to get the SQL right for each of those 30 new forms Jane asked you for last week.