It came out a blink ago and their landing page doesn't even work (the button to get started wasn't clickable for me on Chrome, another google product). I managed to see the product by somehow finding an internal link to it. Reserving judgement till after I've seen its use by non-techie friends. Not even close to being a google advocate, but Facebook is riding the coat-tails of network effects and I'm betting money and time that they won't be the last social network there is. All experiments in the space are interesting to me till the underlying problem's solved.