A family member of mine used to work for a realtor firm in our area. The company would take out expensive newspaper ads every week listing new and exciting properties, open houses, etc. Then the day of the open house the realtor would put up signs and balloons on the adjacent streets. The firm started looking to save money when the market dropped so they started asking potential buyers what brought them to the open houses. The number one answer was "the balloons". So the firm figured why spend money on the ads if they are not working. So they pulled all ads and at the same time open house visits dropped off a cliff. The execs were left scratching their heads. They reran a test batch of ads again and the visits picked back up.
The point is that by the time someone gets to your site they have been through a couple steps. They have thought about an idea, likely seen a project going on somewhere, looked for contractors, seen or heard about your outfit, searched the internet, etc. If you ask them they will likely say "the website" is how they found you, but the truth is that is several steps removed. Having a web presence can be effective, but it takes more than a simple page. However, having a simple, well done page with links to it is far better than having bad and incomplete pages, mixed with garbage links and the occasional bad review. A web presence should be nothing more than an extension of your business. Forget facebook and twitter, show who you are and what you do and it is not OK to mix that with your personal life, cat photos, or anything other than the above.