How to connect USB keyboard to iPad

One of the things that i really like about the camera connection kit on the ipad is that you can connect keyboards to the ipad and use them to type instead of the on screen keyboard. One interesting find that i have found is that the apple wired keyboard does not work with this but my dell one does... that really does not make a lot of sense to me. Why would you allow a dell keyboard to work on and Apple iPad but not allow a keyboard made by the same company to be used on it? Let me know what you think in the comments below.