Social Networking in Purchases

I'm sure you've seen "user ratings" on many on-line shopping sites. If you like the product you purchased, you write about it. If you didn't like it, you write about that.

For an example, check out my review of a ceiling fan at Costco.com. (Search for "RobPDX".)

It feels very empowering to be able to give that feedback.

Notice that the fan's "home page" at Costco.com lists the rating above the price. Also above the price is the ability to "Share this Product".

Gary Hamel recently wrote in his blog at The Wall Street Journal:

The Internet has produced a dramatic shift in bargaining power — from producers to consumers. Armed with near perfect information, customers are able to batter down prices on just about everything. For many companies, well-informed customers are now a bigger threat to margins than well-armed competitors.

How can we use this idea of "customer ratings" to enhance our outreach? Is this completely a retail idea?