Do you treat usability as an important aspect ?

While working on usability aspects of menu (and other controls) for my news reader application "whiz", I read important aspects of usability posted by Jacob Nielsen who is considered "Guru of Usability".

Usability is defined by five quality components:

• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• Satisfaction: How pleasant is it to use the design?

Follow this link to read on basic usability principles and more.....

http://www.useit.com/alertbox/20030825.html

I think usability should be one of the most important aspect for any developer, designer, manager, BA etc and one should give usability the topmost priority. Designing systems that make sense to code warriors will often lead to a site that is not usable by the average person.

Jacob Nielsen correctly points out "For intranets, usability is a matter of employee productivity. Time users waste being lost on your intranet or pondering difficult instructions is money you waste by paying them to be at work without getting work done."

According to Jacob Nielsen, sites that spent 10% of their budget on usability reaped a 100% increase in sales/conversion rates.