It's pretty bizarre how 4chan of all places turned out to be the cultural epicenter of this generation. All these meme pages are just reposting content from there.
Now I'd say Reddit is a huge influencer but it is fragmented (as opposed to a single /b/) and still tied to internet points. And missing the pink babies from Something Awful.
Therefore the /b/ experience, although often trashy at best, vulgar and hateful at worst, does allow good content to organically bubble to the top, and not just by absent-mindedly clicking the 'reblog'/'retweet'/'share' button, but by individuals uploading the same saved image or composing a derivative work. It's the internet equivalent of one-off barroom quips, of graffiti in bathroom stalls, of spray paint tags on urban blight. It's us humans at some of our best, and some of our worst.
While I love[1] the idea of having a place for ephemeral anonymous communicationj, that may have been only a local feature. As Jason Scott said[2], "You're like, 'No one notices if I post on 4chan.' [...] I have ten million archived threads of 4chan, for five years." I'm sure that number has grown in the years since he said that. 4chan only seems ephemeral.
[1] I totally agree about /b/ (and the rest of 4chan) being raw unfiltered humanity; it's a lot of junk, a few examples of humanity at its worst, and a handful of creative gems. A majority, I think, is simply people trying to express themselves in new ways. We need a place for that kind of free experimentation.
wired: #dicksout for Harambe
honesty fosters new art