Went to Lamma Island for the past three days. It was great. At least now I know where I wanna live if I stay in HK in the future. Anyway, that later...

Came across the "Secrets of supermarkets" in "HK Magazine". It's rather enlightening:

Secret 1:
Staple needs such as eggs, shampoo etc are always place at the far end of supermarkets whereas perishable products such as bread in bakery are always station at the front of supermarkets so that you got to walk pass all the "non-essential" products sections before reaching to what you REALLY need.

Secret 2:
Companies pay high prices to place products at eye-level of the regular female customer while expensive cereals are normally place at eye-level of children.

Secret 3:
Supermarkets place normal priced products at the end section of racks to increase profits. This works on the misconception of the regular customer that products placed at the end section of racks are always promotional items.

So avoid the traps.