Two principles that Walmart applied during its most successful days were that of EDLP (Everyday Low Prices) and Cluster-based Expansion. Giving discounts brings people. Cluster-based Expansion is a process by which you specifically focus on particular areas and gain greater market share in every such area before expanding to faraway locations. Lowered Transportation, Warehousing Costs because of area concentration and increased visibility and perception in a local market enables stores to have larger profits.
Avenue Supermarts(D-Mart) took this to heart. You can walk into a D-Mart store and receive a discount regardless of whether it is a special occasion or not. How do they manage this? It involves a very complex process that reduces costs aggressively: no decorations, no advertisements, very little employee costs with no IIM Graduates, and hiring of contract labor in the stores. Besides, they buy goods in bulk from suppliers and here bulk means really large. It is a cycle: the everyday discounts ensure greater customer footfall and then D-Mart uses that to get a Trade Discount on the bulk orders from the suppliers they deal with. This Trade Discount goes back to giving more discounts to the customers. D-Mart is also known to make quick payments to its suppliers: they receive a cash discount for paying back in 5 days whereas Big Bazaar, for example, pays back after 30 days. This cash discount is again used to retain customers for the store.