1. List passion.
2. Write problem statements. Checkout groups and forums.
3. Research supply and demand.
4. Find a solution to the problem.
5. Find out if they will pay for the solution.
Sell anything you can think of. Check out CafePress. Search for 'Reprint Rights + Your Topic'. You can sell software, ebooks, paid subscription newsletter, members only site. Use Google suggest : 'How to fix X'.
100:1 is good supply / demand ratio. KEI > 1 is good. Ariel or Verdana, white background, black font. Make sure web page can load faster - compress html. Quantify in headline. Ezine hub, newsletter access, ezine locator.
Top 100,000 rank is good for super affiliate. Ranking, Link popularity. 50 - 100 keywords, key phrases. For keyword tracking use Click Plan