I bought one a few years ago for $59.99 off the infomercial. It was very time consuming. Like Tsmith said, you have to part your hair in small pieces and you have to hold the split ender in certain directions depending on what side of your hair you are doing. I would definitely by another one, since they are only 7.99 now. I dropped mine one to many times and it doesn't work anymore.
Oh yeah, your hair needs to be fairly straight when using it. I think it clips 1/8 of an inch off your ends.