"Every time the proprietor gets tired of a genre of emails, they improve either the internal tools or the business rules to optimize themselves out of that workflow."
I really like this point.. I always think of the FAQ as a bug list. If a question comes up repeatedly enough that people have to start searching for a solution, odds are there are a way more people not asking and you're losing conversions.
This is sometimes phrased as "fix every problem twice," ie solve the immediate problem, and then figure out what to do so this problem doesn't happen again.
This can be done via tweaking your funnel or workflow, adding an FAQ entry, adding tooltips, restructuring your UI to make things intuitive, solving a technical glitch, etc.
I really like this point.. I always think of the FAQ as a bug list. If a question comes up repeatedly enough that people have to start searching for a solution, odds are there are a way more people not asking and you're losing conversions.