Most businesses start designing a website on the basis of what it looks like. In many cases they will start with an existing site and pay a designer to revamp all the graphics and navigation to improve the appearance of pages.

Once implemented there is a period of anxious waiting to see how the new site performs. Will it get more traffic? Will it convert that traffic into sales better? Will customers like it more?

But if you think about it, the best way to design a site is to create some test pages and see how they do. Don't focus on graphics or typefaces or layout or navigation.

Focus purely on conversion. Spend your time and money designing the best converting web page before you do anything else.

Once you have tested different pages, different headlines, different fonts, different graphics etc, and identified the best performer with statistically valid data, then is the time to roll out the design.

Don't make the design mistake nearly all sites make of designing a new site, launching it and then testing it. This web design error happens much more often than you might expect.

Remember at all times what you really want your site to do. Aim for your most wanted response.

You want sales leads if you are selling. You want effective answers to support needs if you are delivering online support.

The only time you want the prettiest looking site is if you are entering a competition for the prettiest looking site.

On top of this you do need to pay attention to some house-keeping. Make sure all links work. Make sure you have an effective alternative to a 404 page. Make sure that if someone types in yourdomainname.com instead of www.yourdomainname.com that you site still appears.

And never ever put in doorway pages that force the visitor to watch a Flash video before they can access your site.