Wasn't there something called tribal fusion or something similar many years ago, amongst several others. Personally, I can't see the point, for example, if I were a product site, I wouldn't some 3rd party able to spew messages all over it, so at best, getting sites to pay you is probably not a business model. But good luck anyway.
"No idea's original, there's nothing new under the sun \ It's never what you do, but how it's done" - Nas
Indeed, but what is different about your take on this idea that has failed many times in the past, apart from slick UI?