1 : This one is to create an impression that this store is very popular [ I just 'sacrifice' my time & effort to promote their shopping centre - no personal profit ]

6 A : Because that free perfume's aroma is for fellow
shoppers not for me.[ Doing 'for others' benefit ]

6 B : I need free food becaue my energy is being
used while strolling in their mall. [ No gain ]