Why is a good domain name important?

A good domain name helps you in numerous ways.
For Businesses

Add your domain name to your business card, email signature, and other advertisements.
Build credibility: Show your customers that you have an established business.
Improve your marketing: Provide customers an easy way to remember and contact you.
Protect your brand: Secure the domain name that best represents your business name — and keep it out of the hands of your competitors.
For Consumers
Describe your site as best you can with your domain name. For example, a pair of amateur magicians might use their stage names, some combination of words including magic, or the name of their most famous trick.