Roger,

            When considering scaling, you should consider not only whether content production is scalable but also whether the method of publishing is scalable. For instance, it is much more scalable for reviewers to publish reviews on their own sites than it is to have everyone forced to publish content in centralized, wall-garden sites like Amazon, eBay, Monster, IMDB, etc.

            I recently wrote a post on the “Gray Web” and how it will be impacted by the combination of Structured Blogging and Prospective Search technologies. I think you’ll find it interesting since it directly addresses the scalability issues you brought up. See:

http://bobwyman.pubsub.com/main/2005/05/mary_hodder_poi.html

                        bob wyman