It was one of the best times with a book. It is my first book of Gail Carson Levine. I don't know if she had made so many great metaphors by chance or on purpose, intentionally. If the latter, she is brilliant. In this case (and I see this book like that) we haven't just ordinary fairy tale. 
 Yes, you has fairies, elves, magic, curses and so on. Yes, the whole atmosphere is like from a good, classic fairy tale. 
 But... You have a lot more. The description of a relationship between ogres and people seems like our relationship with livestock or even with wild animals. Not only because we eat livestock and ogres eat people, but because of complicated emotions to the living creatures, which one want to eat. Every vegetarian and everybody who has thoughts of this from time to time understands this. 
 Secondly, the whole concept of a spell like of being obedient shows a reader how our a character trait might make us a slave. It isn't that only a curse can force us to doing some things. Sometimes our inclinations force our decisions too. For example, if one is shy, even if one wants to go somewhere, one feels so pressure and stress that one gives up going to there. (view spoiler)[And when a heroine receives orders to feel a pleasure of fulfilling orders and then loses this plasure - a masterpiece of human psychology. (hide spoiler)] 
 Next, there is good comparison (between the lines) between magic and religion. An explanation of a big magic and its consequences sounds like an explanation of prayers and their consequences. [See last quote with *] 
 By the way, it is a very interesting (for me, the better than original) version of a cinderella story. 
 It is rather short book and well written. 
 Don't think twice - read it. 
 My favorite quotes: 
 "Everyone called it losing Mother, but she wasn't lost. She was gone, and no matter where I went -- another town, another country, Fairyland, or Gnome Caverns -- I wouldn't find her" 
 "I refused to love it. He was going to sell it too" 
 "But sleep was busy elsewhere" 
 " I wished I could spend the rest of my life as a child, being slightly crushed by someone who loved me." 
 * 
 ""We don't do big magic. Lucinda's the only one. It's too dangerous." 
 "What's dangerous about ending a storm?" 
 "Maybe nothing, maybe something. Use your imagination." 
 "Clear skies would be good. People could go outside." 
 "Use your imagination," Mandy repeated. 
 I thought. "The grass needs rain. The crops need rain." 
 "More," Mandy said. 
 "Maybe a bandit was going to rob someone, and he isn't doing it because of the weather." 
 "That's right. Or maybe I'd start a drought, and then I'd have to fix that because I started it. And then maybe the rain I sent would knock down a branch and smash in the roof of a house, and I'd have to fix that too." 
 "That wouldn't be your fault. The owners should have built a stronger roof." 
 "Maybe, maybe not. Or maybe I'd cause a flood and people would be killed. That's the problem with big magic. I only do little magic"