Getting staff involved is the key to successful up take of your site
Unless you're the dedicated "web manager" for your company - when was the last time you took a look at your company's website? Do you for example know what is on it? Do you regularly refer clients to it for more information? If you do, do other people in your organisation follow your example?
A classic example: someone rings up a company and wants to know about that company's products / services. A sales person could spend 30 minutes describing the products on the phone, but the old adage that a picture tells a 1000 words is so true.
What the sales person could do instead is give a shorter spiel, and maybe ask the user whether they are in front of the computer. If the answer is yes - the sales person can guide the potential client to the website to get more detailed information.
This improves customer service (i.e. the customer will have a better idea about the product / service) and reduce the time taken for a sales person to process the enquiry (making the sales person happy - and saving the company money). This will also free up this sales person for other customers. The customer may also explore other options on your website, as well as print off information for future reference, or bookmark your site to return to in the future.
If you expand this idea to all staff regardless of their position (because at some stage all staff have contact with the customer) you can obviously see the benefits for the company, staff and customers.
Most companies hold regular staff meetings (wether they be the entire staff or in smaller groups). Management should encourage their staff to visit the company site (or demonstrate it there and then) and highlight which information is useful to them and their customers. You can also gain valuable insight from staff about what they would like to see on the site (i.e. a staff member in accounts may say "I have to email this form to 20 new customers per week it would be great if people could download it from the website instead").
Advertising your site is important but can be costly, but utilizing an existing resource (staff) has negligible cost and in most cases reduces staff time dealing with customers yet improves customer service.