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.
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: