well, say what you will, i notice increasing traffic when posting to non-SE , SE submitting sites and apps. Increases backlinks potentially, but, as ive read, this can be good or bad so its more like a study. You run tests on 5 domains doing it without any submissions, only posting your site on sites that allow and are completely relevant to your topic and you do the latter and post on all SE's and sites / apps that post for you. Just remember , these sites will sometimes post on the same backlinks sites.(This does not help you.) ----Before anyone tries to reply and say im wrong, this is all my opinion, based on doing just that myself, resulting in my findings being of what I mentioned above. Now this doesnt mean itll work for everyone, as maybe some topic are penalized for being overly backlinked and/or multiple times at one site while maybe others arnt(?)-- Get a job at google then put the answer, because until then, to each their own but no one knows 100%. my 2c