Cheap knock-offs, off brands, etc. will raise questions about the quality of your business. Of course, a company that is selling a new product or carries products by an unknown manufacturer is at a disadvantage. Expensive branding efforts do effect customer perception of the store that carries those goods. You'll need to demonstrate that products by unknown manufacturers are equal or superior to the established brands. The burden is on the storeowner to make the case.
Brands breed confidence.
Most customers distrust products promoted with hype and unbelievable claims. Though exaggeration can be effective with some shoppers, with many, wild claims will backfire. The storeowner needs to present products in such a way that all of a shopper's anticipated questions are answered in a believable manner. Too many sites restrict ways in which potential customers can ask questions and make contact. This breeds frustration and distrust.