I've come across so many people raving about this book. Well, I finally read it yesterday and I think I know why people like it so much.
It isn't the pictures, clear and attractive and brightly coloured as they are. It isn't even the good story line, with nested three-fold plot structure, satisfying as that is. (A good story line is essential)
Nor is it the appeal of the principal characters, cunning and charming and creative though they may be.
No, what really makes this book wonderful is that it is impossible to read it without rhythm. The rhymes really work, the metre really works, the assonances flow along... and before you know it "that's the end of Gruffalo story".
Too many children's books are full of lines like
"the butcher, the baker, the candlstick maker,
they all jumped over a hot potato"
Go on. Make that rhyme. Blech.