There is only branding. What is troubling about your reasoning is that you seem to have just discovered this principle now. You misinterpret the important statistic that only one in four online shoppers is an online buyer to mean that branding is lacking on the Web, when in fact consumers use the Web precisely because they can compare prices and features of branded products they already know. It doesn't matter to the brand marketer where the product is sold, so long as the customer is satisfied. Branding is first and foremost about products.
Retailers have brands too, but consumers buy stuff.
You need to lift your head and take a peek out at the real world once in a while. As important as the virtual store world is and will be, it is still a business in its infancy. Brands will certainly be built in this sector. Some will be of huge importance. But in the end, the Web will be just one more channel of product distribution for the real mega-brands.