If you had a store on a city street, you'd want to show an attractive sign and window display to pull in passers-by. The online world is pretty much the same, except that your passers-by are passing by a lot faster. Entrepreneur magazine estimates that you have about five seconds to get and keep someone's attention, so you better make that exposure count [source: Shandrow].
The good news is that you can learn to design a beautiful website by using resources such as Lifehacker.com's free "night school" for web design. Once you've mastered HTML and CSS (the codes your browser reads to determine the look of your site), you can design your website from scratch. Or cheat a little by using a website template with the design already in place. All you have to do is customize it.
In addition to a website that looks good on computers, you need one that will display well on tablets and smartphones. A 2014 analysis by Shopify, an ecommerce shop builder, found that more than half of the traffic going to online stores that use its platform now comes from mobile hand-held devices [source: Lutke].
So make sure your website has a responsive design, one that can accommodate both big-screen and small-screen customers. There are websites (like Mofuse) that help you create mobile versions of existing websites.