No one can write a best-seller by taking thought. The slightest touch of insincerity blurs its appeal. The writer who keeps his tongue in his cheek, who knows that he is writing for fools and that, therefore, he had better write like a fool, makes a respectable living out of serials and novelettes; but he will never make the vast, the blaring, half a million success. That comes of blended sincerity and vitality.