The most important chain life factor is lubrication. The most effective available lubricant I know of is "Chain-L" (Home Page Chain-L High Mileage Bicycle Chain Lubricant). It works simply because it is thick enough to 'stay put', excludes dirt and -- most importantly -- keeps the moving parts , well -- apart.

True Believers and suppliers make this matter more complicated than it has to be; chains need thick, sticky oil. Period!

Joe