O-Gloss

I am breaking the mold a little bit with this one...I actually don't know if this product is lovely or not. Two of my friends recommended Smashbox's liquid cheek stain O-Glow to me last Spring. It goes on clear and transforms to your natural blush. I really love the look...although immediately after applying it the hue is more intense than you would like, it gradually fades to a pretty pink flush. The idea behind this product seems logical to me because people blush naturally. Now that Smashbox has created O-Gloss, the logic behind the product is less clear. Our lips don't blush or change in color in the same manner our cheeks do, however, the product reacts with our chemistry to transform into a custom shade. I need more information...what custom shade? How does it differ between users? Have any of you tried this? Interestingly enough, I participated in an online marketing survey for O-Gloss prior to the product launch and my questions were the same. Apparently, my curiosity is best addressed by going out and buying the product, which leads me to the conclusion that their advertising is more effective than I give them credit for.