In the first chapter, Woods notes that Schopenhauer had a bigger influence on creative writers than on philosophical protégés. The reason for the lack of followers, I would say, is that he never held a powerful academic position and instead alienated other philosophers. (He particularly hated Hegel.) The reason for his literary admirers is his clear and entertaining writing style, unusual among German philosophers of the period.
My favorite story comes near the end, when Schopenhauer rents rooms from a family with small children. He appears so grumpy and intimidating that the parents discipline their kids by threatening to report their misbehavior to Herr Schopenhauer. Pretty quickly, though, little Lucia fell in love with Schopenhauer's poodle and ended up spending long hours in his rooms cuddling with the dog.