I don't want to be dismissive, if you have some kind of distinction you're trying to get at, I'm open to hearing it. But I personally don't see a big conceptual difference between Reddit and a forum, other than that one of them happened to get bigger. And I'm pretty skeptical of using size as a criteria here, because it would force us to say that Google+ and MySpace stopped being social media at some point when they dipped in popularity.
The distinction I was going for was things that predate the classification terminology. I guess there's no particular reason not to apply such classification retroactively, but it feels a bit weird considering that in the heyday of these technologies, few if any people referred to them as social media. Seems a bit like saying "let's stream some music" as you're loading up a CD player. Technically yes there is a stream of bits but it just seems silly to speak in such terms.
I don't want to be dismissive, if you have some kind of distinction you're trying to get at, I'm open to hearing it. But I personally don't see a big conceptual difference between Reddit and a forum, other than that one of them happened to get bigger. And I'm pretty skeptical of using size as a criteria here, because it would force us to say that Google+ and MySpace stopped being social media at some point when they dipped in popularity.