Yeah, but not on pies, oil, jam, and second-hand clothes (unless that's really their business, which doesn't appear to be the case here).
Anyway, this is probably even less significant than changing banks to credit unions :-)
FWIW, NPR did this story over a year ago:
http://www.npr.org/2011/11/29/142908549/modern-greeks-return-to-ancient-system-of-barter
/jordan