Do I need a website?
As far as web-literate consumers are concerned, internet search engines generally offer the best way to track down a local plumber or find out where the local pet shop is based. This is true of businesses looking for a new supplier or potential clients.

Be seen and heard
Whilst a website doesn't guarantee the instant it goes live you will start receiving phonecall after phonecall, it is a good way for potential customers to find out where you are, what sort of product/services you offer and peace of mind that you have taken the time to show the world what you have to offer.

Another thing
The reason why so many companies are disappointed with their website's performance is that they have failed to maximise their potential. It's a passive device and unless you have a well recognised brand name you need to have some way for people to find your site. If you haven't marketed it properly, it's like taking a bunch of brochures, putting them in a cupboard and then wondering why sales aren't going up. Thats where SEO comes into it's own.