According to a service that tracks such things, the most popular types of websites people put for which there is a subscription fee include (in order from most to least popular)
* How to lose weight * Health products - Vitamins, minerals, colon blow * Starting a home-based business * How to make money from your existing business * How to market on the Internet * How to make money through investments * Personal improvement * How to turn a hobby into a business * How to move to a new state/country * How to practice your religion
I'm not sure why, but I find this list incredibly sad. There are so many decent sites out there that give this information away, and most of what's behind the paywalls is pure bullshit not worth the pixels it's drawn with.
This just confirms what one commenter said earlier: most people don't want a well-made website. Well-made websites scare people into thinking there's trickery, deceit, and too much intelligence behind them for the individual to keep up with. Stupidity sells.