Do you consider charity shops non commercial?

[Tristan Hill <tristan+201204@saticed.me.uk>]

Hi,

I volunteer in a charity shop in the UK (details of the charity can be 
seen on http://www.wnaa.co.uk/, basically we fund helicopter ambulances, 
there is no charge for this service) and would like to find out if 
playing CC by-nc-sa licensed (from http://magnatune.com/) music in the 
public space of the shop counts as non commercial.

I have seen the text referring to non commercial on 
http://magnatune.com/info/licensing, which refers to the text of the 
by-nc-sa license.  My understanding of this text would be there is no 
intent for commercial advantage so would meet the terms of the license. 
 However, I would like to clarify this for sake of the charity.  Have 
you come across this situation before or otherwise comment?

Thanks
Tristan