CDs don't sell unless the prospective buyer has heard the performer recently. I'd guess that virtually all local performers' CDs are sold at concerts.
This is an uncomforable truth for one in the CD selling business to face. I've found that even CDs by well-known and respected UK performers don't sell in the US , unless the performer has been touring over here: CDs by the likes of Pete Coe and John Connoly just don't sell over here.