There are some things I'd like to expand on, though - as the additional notes on that little game acknowledge, there are lots of other ways to model both the networks connecting people and the ideas that spread across those networks.
In particular, I'd like to add a couple notes about groupthink and what happens when we have multiple competing ideas. If I could pick one thing I wanted to add to the simulations in the above presentation, it would be to have multiple competing ideas, and belief in one or more ideas would change the chances or required exposure that the competition needed to spread. A close second would be to add more types of relationships to reflect the fact that we're more likely to believe something a few close friends believe than we are to adopt something even a huge number of distant acquaintances believe.
I'm not sure how that would change the result, admittedly! I don't think the advice the presentation closes with - pay attention to how your network affects ideas, put in the effort to build a good one that includes bonds with people like and unlike you, be skeptical of ideas that flatter you, and take the time to understand complex ideas - would change much. But I can't help but feel there's more to encouraging the spread of good ideas than that, and I'm really glad to see things like this presentation that might encourage all sorts of people, including me, to think about it a little more.