OK I did it the recommended number of times, and really saw no huge difference. I read on another board that if you're teeth are already reasonably white, it won't work too well. Luckily, I saw their money back guarantee and asked for my money back. All I have to do is return the product, and they will not bill me for the next two payments and then give me 30% off the first payment I made. Not bad. I'm pretty happy with that, b/c I did not want to spend $90 on something that didn't work for me.
The guy said I had to make sure they got it by May 9, so I might just try it some more to see if I can get better results and send it back in anyway.
I do think if you're teeth are yellow and you've never tried a whitening product before it would work. I've gone through boxes of whitestrips and I don't think it did much on me.