What's in a name? What can a good domain do for your company?
A good domain is a great way of showing professionalism for very little cost. If you had two plasterers in mind for a job, and one had the e-mail address of danny-x-the-x-xplasterer-78@hotmail.com and the other one was danny@plastering.co.uk (neither of these are real addresses that I am aware of, purely an example) then which one would you choose?
Also when it comes to Websites some domains can be short snappy and to the point, others seem to trail on forever which can be confusing and can often get mistyped into browsers. The point of this paragraph is to say; Keep It Simple.
Dansplastering.co.uk would be much better than dan-the-plasterer-from-wolverhampton.co.uk - Even though the second actually tells you more about the business, the first is much more memorable.
Think of a good domain like a good phone number, if it's easy to remember, it's more likely to be used.
In conclusion, a good domain should be short and snappy to aid memorability, but also it displays an air of professionalism. It's not expensive, easy to use (especially with services such as Gmail hooking into your own domain based email), and you should make back the expense with your first job!