In other words, that in order to spread, a thing (or idea or word) must have something special about it; that it must be something about the thing that makes it spreadable (or "sticky") if you prefer that term.
This works both ahead of time (in our attempts to predict what will spread) and also in retrospect (in post-rationalizing why a particular item has spread and become popular) - darn, are we good at the post-rationalizing success based on some spurious quality of the thing (Subo is a great e.g. of this).
This is such a plausible assumption that for many of us it enjoys the status of self-evident truth. But is it actually true?
Well, sometimes it is and sometimes it isn't. And perhaps more often than not in our modern oversupplied decision landscape - where we are faced with too many effectively interchangeable and indistinct choices.
You see, if diffusion is genuinely social - if the spread is genuniely shaped by people following the example of others, the people are as important if not more so than the thing and its qualities in determining the spread.
For example, if a thing is spread by a population tending to follow the example and recommendation of experts or authorities, then its spread will then tend to depend on who those experts are, how visible they and their enthusiasm are etc etc.
Equally if a thing is spread by a population copying in a less directed way (what we've called Copying Peers) - i.e. just following what seems to be popular then again an individual's perception of what other people are doing is essential to the spread of the thing. (this is is an example of what we disparagingly call "fashionable" choices, do denote the relative unimportance of the thing).
[For more details see the 4 box map which lies at the heart of "I'll Have What She's Having - mapping social behaviour"- these two represent the Eastern portion of that map.]
All of which means that if you want to spread something, ask yourself if it's likely to be spread socially or not and worry rather less about the thing thing and more about the people thing,
And don't be surprised if your really good thing doesn't spread or something really pony does become really popular. Where people-based spread isa concerned, it's a matter of bets, of chance and the unpredictability of what people take from each other. It's a people thing, man.
And don't be surprised if your attempts to replicate a success are less than successful. Again, the people thing makes repeated success much less likely than you'd think.