I think this sinks "viral" for now, at least as a strict analogy to epidemiology.
I can count on one hand the number of times where I have forwarded something, or had forwarded to me, something that was "viral".
Every "viral" meme I've ever seen came from a specific broadcast-dominant system. Whether it be Slashdot, Reddit, HN and so on; I've gotten 'infected' simultaneously with thousands or millions of other people. There was no peer-to-peer spread, merely a direct fanout to individuals.
Whenever my friends and I have commented on a current meme, we've been synchronised to within about 48 hours by the propagation of memes between websites, not people.
I can count on one hand the number of times where I have forwarded something, or had forwarded to me, something that was "viral".
Every "viral" meme I've ever seen came from a specific broadcast-dominant system. Whether it be Slashdot, Reddit, HN and so on; I've gotten 'infected' simultaneously with thousands or millions of other people. There was no peer-to-peer spread, merely a direct fanout to individuals.
Whenever my friends and I have commented on a current meme, we've been synchronised to within about 48 hours by the propagation of memes between websites, not people.