Speaking of on-demand content . . .
Right after finishing my last post, I saw this post on Ensight about a site called Constant Content that Jeremy Wright, author of Ensight, helped develop.
The site allows you to buy or get (for free) content to use on your own site. You can download chunks of code, articles, reviews, tutorials, etc. If you author something that the site sells, you make a 50% commission.
I'll certainly be keeping my eyes on how successful this site is.