Economics are primarily about competition. This is why we have brand name and generic products in any market. A generic product allows a consumer to get a nearly identical product as the brand name for a fraction of the price, and that is why they are able to compete on the market. This is why there will always be a market for things like Replica Designer Handbags. In regards to things like Replica Designer Handbags, there certainly are people who would contend that they are not quite the quality of the brand named handbags that they are replicas of; however, for many people the look is the most important thing, and the amount of monetary savings that come with the replicas is something that the brand names simply cannot compete with.
Because of competition, there will always be a market for knock-off and generic brands when it comes to the different products on the market. The educated consumer compares quality and price and makes a decision based upon that. Some people value the quality of a product to a point where they are willing to pay the highest price possible in order to get that brand name product. However, there is little difference between generic and name brands, and that is why many people find more value in the generic brands.
Ultimately, the decision comes down to what the individual consumer values. If you are rich and looking for a status symbol, you are more likely to purchase the name brand so that you can brag to everyone in regards to your financial status. If you want the best product for the best price, however, you are probably more likely to purchase the off brand because it will give you the best possible value for your dollar.