Though both stories are told by third person narrators, Harry Potter's narrator is much closer to the main characters. The narrator shows us the story as the life of Harry and his friends progresses, telling us about all the interesting things that happen around them in detail. The narrator of A Wizard of Earthsea on the other hand, is more distant from the protagonist. I simply can't fully feel for Ged. Of course, in many parts of the story I really, really hate Harry and the other protagonists, but the simple fact that I do have a feeling (although it is hate) means that Rowling has been successful in engaging me with her story.
Another point, and this is the more crucial one I believe, is that Rowling uses much less exposition in her books, than Le Guin does in hers. Though Le Guin's prose is much better than Rowling's, still someone is telling me (albeit in a wonderful prose) what is going on all the way through the story. In Harry Potter, I simply see events as they unfold. Following the old "Show, don't tell" advice here makes Rowling the clear winner.
This is more of a reminder to myself. When I write a story, I want to be able to enjoy reading it like I do when reading Harry Potter. Indeed, aside from Stanislaw Lem's The Invincible, there is no other book I have read over and over again more than Harry Potter books.
So dear Homayoon, if you want people like your stories, read Harry Potter even more, and learn showing your readers what is going on. Avoid exposition at all costs!
