This already sort of happens. Many larger sites, places like HuffPo or TechCrunch, accept contributions from outside contributors. You get paid a tiny bit, and

This already sort of happens. Many larger sites, places like HuffPo or TechCrunch, accept contributions from outside contributors. You get paid a tiny bit, and then you get to link back to your own site, so you get a little marketing juice too. A platform would be interesting too, but it’d be hard to curate without all the standard race to the bottom tactics that people would use to exploit your page rank. In some sense, you can’t avoid the need to commit to a brand and a voice. So the way to achieve what you want is by federating with other brands and voices, not dumping into an anonymous platform.