There is an article in "Customer Loyalty and experience design in e-business" Design Management Review by Karl Long that really nails what good interface design is all about I think. It all comes down to these four items:
- Trust
- Competence
- Autonomy
- Enjoyment
Basically trust is the cornerstone of the developing customer loyalty. IMHO Google exemplifies this in a great way. Yahoo does too to a certain extent. There isn't anything invasive in their online products yet they are functional enough to allow to get done what I want to do.
Competence is the concept that that a website should make the user feel competent. Sites that are cluttered with ads and headlines of 'quasi' news erode that actually. Most marketers don't really get it yet that more is not always better. Also if things are to difficult to use that can really erode a users feelings of being competent.
Tying into this competence concept is the idea of autonomy. In other words the ability to allow the user to control their own destiny. Many times we as developers feel the need to handhold the user through a particular process. By allowing the user to learn the interface (as long as it is easy to learn) you give them the sense that they are controlling what the outcome is thus making them feel empowered.
