discout ,discount, discount ""||||""

Suppose we go in shop and their we see 50% of discount on top or Jean's or in any product, then we go and definitely buy it because the offer is only for 1-2 day, so I think that when we go in shopping mall we see everyday there are many discount in every products that we go for buy only 1product but when we come home we buy 10 more products but  why this happen,?how discount is a king, so let's understand about it

We have heard the names of some companies such as wallmart, COSTICO, WAMA, we think that how they so much profit with discount, when we see in shop there is never a concept of discount but if you are an old customer of that shop then definitely they give discount. 

But how this company is king for market, let's understand  by some points:-

1) volume of sales :-  the company have many stores and in every city or town they have their own building and land so if they sell in less net margin and if they do discount at 20-30% definitely the customer attract from them and it helps to understand that they deal with every factory and their members. 

2) advanced supply chain margin :- they have such a new technology they use such as upc codes, tags, and know every small information that what, how, where the another department is selling that product and they have additional manufacturing wholeseller, and they have a power that they can buy from factory by more discounts. 

3)Minimizing of operational and overhead cost

:- they have part time workers, as they pay less to them, they have full time workers by whom they pay less and they have their own land and they have their own truck so that it helps to save money from this costs. 

4) leveraging of its bargaining power to focus on supplier for lower prices:- 

In departmental store the factory dealer have to sale 40-50% of discount and in cheap prices, because every department has a power to sell their  product in their stores, so factory dealer have to sell in less price

By this points, it helps to understand why this company give so much discount.