Your site should give off a great first impression, be easy to use, simple to understand and encourage your visitor to act. To become a customer, not just a browser.
Your website must look good and work fast. Customers should understand what you do and get what they want within three clicks.

Responsive Web design, which aims to develop sites offering an optimum reading and navigation experience for the user, regardless of its range of devices (mobile phones, tablets, readers, desktop monitors).
A successful "Responsive" user experience involves minimal resizing (zooming), cropping, and multidirectional page scrolling.