If your users have many questions, it's a failure of your primary site design. It becomes not so much customer support, as much as customer complaints.

On the Web, all advantages are temporary, and you must keep innovating to stay ahead

Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

Windows '98 is so similar to Windows '95 because Apple hasn't invented anything worth copying since 1995.

Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.

Developing fewer features allows you to conserve development resources and spend more time refining those features that users really need. Fewer features mean fewer things to confuse users, less risk of user errors, less description and documentation, and therefore simpler Help content. Removing any one feature automatically increases the usability of the remaining ones.

To design an easy-to-use interface, pay attention to what users do, not what they say. Self-reported claims are unreliable, as are user speculations about future behavior.