I tend to read what I like, and I know that what I like is not what someone else might like. I may give 3 stars to a book that someone else gives 5 stars. For me it is about personal taste. If the book takes me away from the present into the book's world and I don't want to come back from it, then I am likely to give it 5 stars. A book that has a great plot, engaging characters, is well written, and makes me think about my life and others, usually gets a big tick.
Recently on Amazon I gave one star to a book that 23 others had given 5 stars. The plot was good but the writing was pedestrian. I skim read it. That's the trouble with a Kindle, I buy more books that are likely to not be to my taste. I must put the brake on and be a little more discerning. Not get fooled by a lot of top stars in one place, note to self check it out elsewhere first.
I have heaps of books in my TBR pile, eek - sometimes I have bought a book twice unknowingly. One in on my Kindle and in paperback. I hate that. Because I have a large TBR pile I am going to begin 2013 by taking part in a challenge directed to whittling down the TBR pile. Really? I guess there won't be any whittling down, because while I am reading from it, I am adding to it.