Providing predictable, meaningful, clear feedback to users to help inform and guide their interactions with your site (kinda like this).
It is no secret, clear and usable sites are best practice and provide welcome relief to a visitor on the often visually overwhelming world-wide-web. However, importantly for businesses, that same predictability and clarity in UX translates to trust in a brand. It's not rocket science (or even parallax effect ;) if someone isn't reliable and clear with you don't you question their trustworthiness? Same with UX.
I love every aspect of web development: creative collaboration, writing code, design, logic, problem solving, more code, scripting, usability and analytics. If you are still reading this you should probably send me a message :)