Corners

Every time ISIS manage to effect some atrocity they're always seen carrying that black flag of theirs. Now there can't be too many flag manufacturers that are willing to make ISIS flags; you can't just pick one up on eBay or go round to your local corner shop and buy one. So it seems to me that if only the forces ranged against them could find that factory and destroy it, then ISIS will suffer a major blow to their prestige.

Here's a conundrum; corner shops are, obviously, on corners, but that is it about the corners of streets that makes the buildings particularly suited to shops - could it be the extra window display space, or are they not ideal for habitation? Lack of a garden, maybe?