Availability entrepreneurs are “social agents who understand the dynamics of availability cascades and seek to exploit their insights. Located anywhere in the social system, including the government, the media, nonprofit organizations, the business sector, and even households, these entrepreneurs attempt to trigger availability cascades likely to advance their own agendas. They do so by fixing people's attention on specific problems, interpreting phenomena in particular ways, and attempting to raise the salience of certain information.”

Marc goes on to say very transparently...

"What am I doing with this blog post? Trying to spark an availability cascade about availability cascades."

It appears that a16z's strategy was successful. You are posting about a16z's blog posts thus contributing to the spread of the blog posts ideas.