Good design means uncluttered layout, not having to scroll through reams of plain text and having image rather than text based links. Good design is about helping users find information and making the sales process as easy and pleasing as possible.

Most web design agencies believe strongly in interactivity. This is the key to user retention. An interactive and customisable site will give users the ability to make the site what they want, so information and services are always at their fingertips.

Interactivity can be achieved through back-end databases or the use of Flash or Java to create dynamic content or interactive feature that keep users coming back...

...but it all adds cost and complexity to your website.  This is where the DIY part separates from a professionally created website.