Russell,
Yes, I think I know what you mean. The answer is a resounding YES.
The main thing is that you get some sort of contact from it (either phone or E-mail).
Do they work? Yes.
Some friends have a business where say, 98% of their work comes from the web. What started of as an e mail enquiry from an interested party turned into several phone conversations. It finished up as a quote for a staggering £ 98,000 of work! Sadly this was not a carpet cleaning business.
A website should be an important part of your marketing armoury.
Best of luck,
Garry