The Holy Grail for many authors is to write a popular book series where readers of book one go on to read book two and so on. Writing a popular book series provides many marketing advantages, namely that your advertising is far more profitable.But writing a series is also risky. Generally, you can only sell subsequent books to folks who purchased, read, and enjoyed the first book in the series.For some authors, writing books in a series has shackled their otherwise good books to a relatively ...