My 8.5yr old daughter brought this home from the school library. When it had to go back, she went and found it in the local public library. When that had to go back and she was *still* reading it regularly, I bought it.
The 'hook' is, I suppose, the 'day-by-day' format - she looks up poems for each person's birthday, for today's date, etc. - which gets her reading all kinds of things. Not being particularly 'into' poetry myself I would not have expected it to be so popular, but she and all her friends love it and I think it will remain precious to her as she gets older. She now thinks of, and can quote, Blake's 'To see the world in a grain of sand' lines as hers (being her birthday date). How cool is that?