To me, the major difference is a proper representation of the source. If Widgets inc pays a person to publish a bunch of influencing articles which are signed

To me, the major difference is a proper representation of the source. If Widgets inc pays a person to publish a bunch of influencing articles which are signed by "Joe Shmoe, social media manager of Widgets, inc", that's appropriate, but if the exact same content would signed by "Joe Shmoe, just a random bloke from Kansas writing my own thoughts about what's wrong in this world", that's misleading.