Interesting, so then the few people who still use match.com (after you filter out scams and such) don't even have to pay for it because they can contact the other person though Facebook once they match the photos.
No because Face.com will only search from a master list of photos you provide. If you go the route of using your Facebook account, it will only identify faces from the pool of your friends.
Technically, they could go further but they don't.
So specifically, this hack is telling you which of your friends are on Match. If you don't already know someone you find on Match, this isn't going to help you (unless Face.com change the way their tool works)
You described something slightly different. The article is about finding a particular person on Facebook on a dating site and you are looking to go in the opposite direction. This means that you would need to scrape Facebook profiles instead. While some people don't make their photos public, this generally shouldn't be any harder.
However, contacting someone directly on Facebook might feel creepy to the recipient in that when they posted on a dating site they expected to be anonymous.
