So, the term 'common currency' is mostly used to talk about currency unions. This is, of course, where more than one political entity - usually a state - use the same currency in the sense of money.
The term used much less frequently in the sense relevant to this blog, which is with reference to decision, pattern in choices, and the processes by which choices are produced. As a result this blog is, so far, barely visible. Except for social traffic from people who pay attention to my personal activity on Facebook and Twitter, there's almost no traffic at all. Part of the problem is the dominance of what for me are irrelevant uses of 'common currency'. Even searching for "common currency brain science blog" doesn't (yet) return results where this site is anywhere near the top.
I'm going to try to take a few steps to improve matters. One of those is signing the blog up on Research Blogging, so that appropriate posts can be digested and appear in their feeds. I'll also see what I can do to generate some more inbound links.