Documents > Who are the users ?
In today's environment, the users have similarities...

They are:

-resistant to change and lazy
-under time pressure
-tasks oriented
-hunting information
-not willing to understand how you are functioning
-only willing to take the risk to change if there is a significant pay-off
-ignoring advertisment or anything that would look like advertisment

They have:

-developed (navigation and surfing) habits
-various levels of technology understanding
-limited attention to your corporate messages

If your users are significantly different from that picture, you might want to ignore usability at all, but otherwise, you better take these factors into account when building new applications, websites, intranets, etc.