I have just learned from one of the customers, who filled out the online survey, about the NPR's Weekend Edition Sunday short, aired on Aug 11, 2013, titled "America, Are You Tough Enough to Drink Real Russian Kvass?"
It definitely seems to raise people's curiosity. I wish I knew about the article early enough, since the NPR staff lists only a couple of kvass manufacturers in the US, which are actually microbreweries specializing in beer. Kolokol Kvass, LLC solely focuses on non-alcoholic kvass production, and to my knowledge, it is the only such entity in all of the USA.
Here is the link to the NPR article about kvass: