My point isn't that Robin is famous among libertarians, it's that he's associated with famous libertarians. When yet another GMU econ professor starts a blog, especially one Bryan Caplan routinely calls one of the sharpest thinkers he knows, libertarians are likely to at least check it out. Also note that Patri Friedman, another famous name in libertarian circles, was one of the original contributors to Overcoming Bias.

I found OB and thus EY through the mechanism I'm describing, so the availability heuristic might be at work here, but my experience at libertarian organizations suggests that I'm not alone* - I've dropped EY's name or mentioned something from the sequences in conversations with libertarians and they often know what I'm talking about.

* Though admittedly, it's been a couple years since I've been to an event put on by a libertarian organization.