Buyers Coop and Barter Network
The culture developing around the use of the World Wide Web is a simple extension of the competitive economy. Typically, websites, which offer economic leverage to consumers, do it through conventional economies of scale (e.g. www.amazon.com) or by pitting customers against each other in the form of on-line auctions (e.g. www.onsale.com). There is another way.
The Buyers Coop would approach producers and establish what kinds of quantity discounts they were willing to provide. Then the website would promote the products at the discounted prices (with a small mark up), and interested customers would sign up on a list and when the list had reached the number required by the producer the order would be placed. The list of customers would form an ad hoc Buyers Cooperative, which could chat amongst each other and provide informal user support if desired. With time the Buyers Coop website would include information like how long it had taken for the last group to form to purchase a lot of goods and product evaluations from buyers.
The small mark-up would cover the costs of several things. One part would be the overhead of the Buyers Coop: web development, vender outreach, consumer protection, marketing, etc. The Buyers Coop would have its principle responsibility be to the customers who used the site. The Buyers Coop would publish on the web a detailed accounting of its operation, to lead by example that the new web culture should require higher levels of transparency in business. It would be a for profit company. 
The initial majority shareholder would be a Barter Network, which would also be the direct recipient of a fraction of the small mark-up. The Barter Network gets at the deeper problem of unsustainable consumerism. If the web simply accelerates the rate of consumption world wide, then there is little chance there will be much let for future generations. We need to use the web to more effectively distribute used goods and enhance money-less economies. The Barter Network would also be web based and work to match various offers with requests through computer and human assisted transactions. [For example, If Chris wants a toaster and has a bike, if Dana wants a bike and has an aquarium and Sky has a toaster and wants an aquarium a trade can be offered across the three].
The Barter Network will also have a barter bank of items offered for free by members of the network to help ease "transaction friction". In the above example if Sky is a bit disappointed by the kind of the aquarium offered by Dana, the Barter Bank might choose to add fish which had been donated to help improve the chances of successful trades. The Barter Network will be a non-profit organization.