Just kidding. http://amzn.to/1oGuIYH > reviews like this. Others I've got as well, but to know that you've touched someone. It's the only reward in writing. It's hard work, if it paid peanuts that'd be a substantial raise, but it's not always entirely thankless and that makes it worth it.
Meeting the characters, hearing their stories? Those are great. Really, it's what drives you to write in the first place and, until you've published, perhaps THAT is the best thing … if only by default since there's no other competition, in my opinion, but once it's out there and people are reading it and responding? That's even more wonderful.