This is a good article "When I bought your book I didn't sign up to be your beta reader" http://vacuousminx.wordpress.com/201...r-beta-reader/
Then there's Elle Lothlorien who changed the endings on her books in response to reviews http://www.digitalbookworld.com/2012...ative-reviews/
Though I do have my issues with her approach because it feels a lot like she bullies people into changing their reviews and "liking her." There's a whole ton of people that really don't like her approach and I've made the conscious choice not to read her stuff. Because I have a finite amount of money and what if I buy the wrong version and get an ending I don't like?
Some people suggest that if you're self-publishing, you should include both versions. Others say sell them as different versions with different covers. Above all, I think people should just be honest. I hate when I buy a book and find out it's just a compilation of stories I've already read and they market it as "new." That's lame and I feel cheated out of my money.