To capitalize on the e-commerce growth, many retailers are making the necessary investments that will allow them to sell their merchandise online. Traditionally, the online channel has been viewed as a separate way to sell products. Nowadays, many firms have realized the need to provide consumers with a seamless shopping experience, which leads to the "omni-channel" retailing. Recent surveys and studies show that consistent products and consistent pricing have been considered as the top 2 most critical attributes of "omni-channel" retailing by consumers. Although a number of theories suggest efficiency and strategic differences between channels, there is virtually no work on combining these into an "omni-channel" studies. In the first chapter, we undertake to close this gap with a theoretical study that focuses on comparing the omni-channel retailing and the traditional multi-channel retailing from the perspective of consistent product and pricing.To do this, we consider a market where there is a single manufacturer who is capable of producing up to two products versions. The manufacturer sells his products through his own online channel and a retailer's traditional brick-and-mortar store; both channels face uncertainty market size and compete against an outside retail market. Under an omni-channel setting, the manufacturer's online channel and the retailer's brick-and-mortar store are required to offer the same product at the same retail price; while under a traditional dual-channel setting, the products and retail prices across the two channels are allowed to be different. We characterize situations when an omni-channel strategy could benefit the manufacturer and the retailer. We first study the centralized supply chain where the manufacturer and the retailer are managed by an integrated firm, and then examine the decentralized supply chain where the manufacturer owns the online channel and an independent retailer owns the brick-and-mortar retail store.We find that in a centralized supply chain, the integrated firm is always worse off under the omni-channel setting since the channel consistency requirement constraints the integrated firm's product offering and pricing decisions. However, in a decentralized supply chain, the omni-channel strategy could benefit both the manufacturer and the retailer in the situations where the competition between the manufacturer's online channel and the retailer's brick-and-mortar is intense and neither channel has clear advantage over the other. This is because through synchronizing product and pricing across channels, both the manufacturer and the retailer are able to reduce competition between the two channels.Besides studying firms' strategies about managing multiple channels, this dissertation also examines firms' product-line expansion strategies and the effects of consumers' fairness behavior on firms' quality and pricing strategies.In the second chapter, we study manufacturers' product line expansion strategies in a supply chain. To expand sales, many manufacturers try to develop and sell product lines. Frequently, however, the distribution of a product line to consumers creates tensions between a manufacturer and a retailer as the retailer may choose to stock only some product versions from a product line created by the manufacturer. To mitigate this tension, previous literature has shown that if a manufacturer (he) wants to sell his product line through a retailer (she) who faces deterministic demand, then he needs to customize the product line design according to her requirements. Also, the design requirements may change across retailers. In contrast, in this chapter we show that if demand is stochastic, then a manufacturer can mitigate the same tension merely by re-allocating inventory risk in the supply chain. Surprisingly, this strategy can be so powerful that it is possible to find cases where the equilibrium product line includes more product versions when the manufacturer sells through a retailer than when he sells directly to consumers.The model in this chapter is a bilateral supply chain with a manufacturer capable of producing multiple product designs and a retailer who faces stochastic consumer demand. The manufacturer sells his output through the retailer using one of the following variations on the classical wholesale contract: push (PH), pull (PL), or instantaneous fulfillment (IF). With PH and PL (IF), wholesale prices and quantities are decided before (after) demand is revealed. Retail prices are always set after demand is revealed. With PH (PL) the retailer (manufacturer) carries retail inventory.Taking the manufacturer's point of view, we characterize the equilibrium product line length and equilibrium contracting strategy. Our answers are determined by three important drivers: demand variability, product substitutability, and the retailer's outside option. Low outside option and low (high) substitutability imply that the manufacturer maximizes his expected profit by offering the retailer longer (shorter) product line using the IF contract. As outside option increases, the equilibrium contract will be either PH or PL. High demand variability and low substitutability imply that the manufacturer should be expected to sell a longer product line with a PH contract. Low demand variability and high substitutability imply that the manufacturer should be expected to sell a shorter product line with a PL contract.In the third chapter, we study the effects of consumers' fairness concerns on firms' quality and pricing decisions. Empirical evidence and behavioral research suggest that consumers may perceive a firm's price as unfair when its profit margin is too high relative to consumers' surplus. Consumers with inequity aversion experience some psychological disutility when buying products at unfair prices.In this chapter, we develop an analytical framework to investigate the effects of consumers' inequity aversion on a firm's optimal pricing and quality decisions. We highlight several findings. First, because of consumers' uncertainty about the firm's cost, the firm's optimal quality may be non-monotone with respect to the degree of consumers' inequity aversion. Second, stronger inequity aversion makes an inefficient firm worse off, but may benefit an efficient firm. Third, stronger inequity aversion by the consumer can actually lower the consumer's monetary payoff (economic surplus) because the firm may reduce its quality to a greater extent than it reduces its price. Lastly, as the expected cost-efficiency in the market decreases, both the expected quality and the social surplus may increase rather than decrease.