So many websites out there are over looking usability aspects. Usability looks at factors and best practices that come into play when designing a website that is going to be readily "used" by the end user. Don't let the word usabiliity scare you. It does not mean that design has to suffer. Instead more and more designers need to look at usability as a good thing. It does not create constraints rather it stretches creativity to come up with ways of making everything flow and "work" but in a way that makes sense from a viewer's common, website viewing behaviours.