It can never be stressed enough. That one word you are probably sick of hearing by now: Reviews. Well, read it again, and again, and yet again, until you are fully convinced that reviews are akin to the Academey Awards.
Reviews, from honest readers, and especially from your fellow authors, should always receive your utmost attention. They will tell you exactly- and sometimes in gruesome, heartbreaking detail, what they thought of your book. At this point, there are two ways you can react to this: tell yourself they don't know what they're talking about, don't they recognize a masterpiece when they see it? Or, you can go running off crying like a little school girl, and refuse to face the reality of your situation. Let me assure you, either of these reactions will be your complete downfall as an author.
Learn to accept both criticism, and advice. If you won't, you are simply dooming yourself to failure, and you might just as well throw out that manuscript you spent months laboring over. I can't imagine why anyone would do that, but hey, it's your tea party.
People don't write reviews just to hurt you, or to have something to rag about. They've spent money on your book, and as a customer, they have a right to voice their satisfaction, or disatisfaction. If you've been careful, and you have a good story- doesn't have to be great, even a good one will do, people will have nothing to complain about. But if you've thrown a story together, slapped a dime store cover on it, and uploaded it... boy, are you going to hear about it, and it would serve you right, if that's what you've done.
Readers are vicious, they will tear you up like a pack of pitbulls. They will chew you up and spit you out into so many pieces your own mother won't recognize you. And those are the nicer ones. The worst part is, readers know readers, and they talk. They can either recommend your book, or warn against it. Absolutely no self-respecting author who has a love for their craft would ever want to be in that postion.
Have pride in your work, but just as important, pour over those reviews- the good, bad, and the really ugly, as if they were a precious treasure being handed to you. Make note of what they say is wrong with your book ( typos, grammar, formatting, etc.) and fix it. That is what will make you a better writer, and certainly one people are much more likely to want to read and recommend.