What you've got is good, but not good enough. If you could just add a little more selection, a few more features and another whistle everyone would love it. But would they love it because they can do anything with it or would they love it because they love the basic idea? People fall in love with the basic idea. Then they discover little nuances, and hopefully love them too. If you want people to fall in love: have a great, basic idea. Then and only then, give more of the little things. Start off with the little things and people won't fall in love...and won't stay around long enough waiting for the great big idea.