Ok, I got an invite and implemented it immediately. I've made over a million bucks from AdSense, been to the 'plex a dozen times, program in a half-dozen languages, built (and sold) a few hundred websites. In other words, I'm pretty savvy when it comes to Google and the Internet.
I couldn't figure it out.
Their instructions are so convoluted, as are their explanation of what it is supposed to do. I implemented it quickly as a test, thinking that it's going to take several attempts to make it work.
I really doubt that there will be a broad appeal to this. It's just too hard to figure out. I'm sure there will be a Wordpress plugin and one for Blogger, but it certainly doesn't pass the "Mother" test. Sorry Mom, I'll stick with Facebook so you can continue to communicate with me.