There are problems with this mode of thought.
(1) Very few people seem to be willing to make their first purchases in a new hobby sight unseen online. Many people are too impatient to even wait for a product to be shipped to them that they have bought, they want their book right now, and if they can't get it, then they will spend their money on something else that they can get right now.
(2) Many new gamers are young. In many cases, too young to have things like credit cards and checking accounts that make online buying even viable. Thus, to have any chance of buying products this way, they would have to wheedle their parents into buying (sight unseen) products for their child's new hobby. This is an added hassle that will likely deter many new gamers.
(3) Despite what you might think, the vast majority of gamers are not online, and have limited, if any, ability to purchase materials on the net. Sure, places like enworld create the illusion that a vast cross section of the rpg fan base is online savvy, but the reality is that we represent a tiny fraction of the gaming community. Walk into an FLGS and ask a random sampling of the customers there about enworld, rpg.net and a couple similar sites, and I would bet you would get mostly confused silence from the patrons in response to your inquiries.
All of which is predicated on the idea that the majority of gamers are on the net and use that as their source of information about rpg materials. This is not the case now, and is unlikely to be the case in the reasonably near future. [/B]