I have used this product for about 4 years now and I absolutely love it! I am a natural blonde but with age (as we all probably know) my naturally bleach blonde hair turned into more of a golden/dirty blonde :( and I did not want that. Since my mom refused to let me dye my hair, I did my research and found this miracle of a product.
It REALLY WORKS! At some point in those past 4 years I got my hair to very very very light (almost looked like it was dyed) blonde that was a beautiful color with streaks of lighter and darker highlights. And that is my favorite part about this product. If you look up close to the the hair (after you've been using it for a while) you will see that there is at least 10 different shades of blonde in that little bunch of hair. It doesn't look tacky as it may seem from my description but rather it looks very beautiful and natural (just like the sun did it ;) ).
I stopped using it for a year because I decided I wanted darker hair and I mean it did look like growing out hair for a while but that's because I was lazy and didn't apply it correctly.
THE BEST WAY TO USE IT:
Make sure your hair is damp but not too wet because you're about to blowdry it until it's dry. Brush your hair out so it's not tangled, apply some heat protectant for all the heat you're about to use on your hair and comb it through again. If you are serious about lightening your hair, I suggest you do it in layers. Section of horizontal layers from bottom to top of your hair and follow this procedure. Spray the product everywhere you'd like to see your hair lightened (I also like to take off the orange flap thing because I just find it annoying while spraying). Make sure to BRUSH YOUR HAIR THROUGH once all the product you want in that layer is in! This is very important because if you don't do this you might end up with a solid line of roots once your hair starts to grow out and it won't look as natural because the color is concentrated in one place. Go through the stands with a blowdryer on hot and high (it burns so take breaks if you need to). Once that layer is dry, move on to the next level until you reach top of your head. By now your hair should be fully dry. If you want you can also straighten your hair after this for the added effect concentrating the heat on the sprayed areas but just be aware of how much heat you're putting on your hair all at once (and don't complain later that it's drying out your hair).
If you would like to have more concentrations in certain areas of your head (such as face framing) then you should take a cotton ball, spray the product on it and then run the cotton ball down the strands you want most product on. I did this for the hair line around my face and it looked amazing!!
I also did only the top half of my hair so that the bottom is still natural and darker than the top layer because I like it and I'm too lazy to go through every hair on my head :P
Lastly, the bad things:
-Just like any hair coloring product, you have to keep up with the roots if they do grow out because this lightness isn't fading away anywhere (FYI)!
-It's challenging to color all of your hair because it's just so much effort. Ask a friend if you have to to make sure you cover all the hair you want lightened with the product. When I went crazy with making my top layers super light, I didn't like how the layers under that were peeking through and were significantly darker than the top :/ Also, don't forget to color the hair when you were to put it in a ponytail but that's just my personal preference.
Overall, this is a WONDERFUL product and I am so glad I found it and I do not look like a box blonde. It's looks natural and beautiful and it's super easy and CHEAP! :)