That's actually an interesting point of view.
It's what a marketer would call "content syndication". Some people also call it "article marketing" (not to be confused with so-called "article
directory marketing" which is something else altogether, and thankfully more or less obsolete, these days).
Do you mean sites such as Reddit and so on? Or actual sites which go out and fetch content automatically?
No; neither.
Reddit, and so on, I consider "social media marketing". (I don't know all that much about it, myself; nor do I believe in it, really). And there's very unlikely to be any real benefit from syndication to "autoblogs" and the like.
My rule of thumb is that I don't want my articles appearing anywhere where they can be published without any editorial approval-process, or quality control. I wouldn't expect to benefit from that.
I offer content (after publishing it on my own sites first, to secure the initial indexations) to relevant sites whose Webmasters I think may welcome additional content, and I supply it - in the form of articles syndicated from my own site - in exchange for a link back to my site at the end. The recipient site gets free content and I get free traffic. I do this only if I like the look of the site and imagine that it actually has traffic I'd welcome and value, myself.
It's very similar, in principle, to "guest blogging" (but a little less interactive).
There's no shortage of Webmasters, including those of some high-quality sites, who syndicate content already published elsewhere, as can be seen from the large numbers of people who look for it in article directories - this being, of course, the exact function that article directories serve.
There's also a minority of Webmasters not too familiar with this method, who confuse "duplicate content" with "syndicated content", confuse "original content" with "unique content" and actually imagine that Google might penalize them for re-publishing such content. This is, needless to say, totally wrong: "duplicate content", for which there are in any case no penalties, refers to multiple copies of text-files
within one domain.
The syndication of content is good enough for many of the world's leading news and sports websites (who take content wholesale from Reuters, Associated Press, and so on), and it
can work well for authors, too.