Portfolio, a bit late, takes note of the great blog rollup, where the selling of blog advertising increasingly becomes the province of big media companies. But blogger Felix Salmon's ignorance of the online-advertising landscape shows. Reuters, far from being the pacesetter as Salmon suggests, is behind the competition. "But it's clear that sooner or later, Big Media's online salesforces are going to be selling ad inventory on third-party blogs," he writes. Really? You don't say?