I spend 10 years of my career life managing intranets. Intranets are very important for a company that is dealing with a changing policies, processes and in service line.
1. Ensure consistency with information provided by customer contact points to customers.
If you do not have a clear and written process documented on a fixed place, your staff may be providing different version or answers based on their own understanding. When the product, process and FAQs are clearly specified, it will leave no room for ambiguity.
2. Reduce potential losses to the company
If a staff provided wrong information that lead to inconveniences or financial lost to the customers, customers may potentially complaint for compensation or take legal action. It is not fair for the staff if there is no reliable source to check or the fact is that the staff did try to ask for help but did not receive the help that was required.
3. Referring to corporate website for knowledge based articles to answer the customer is not enough
I know some companies do not have any internal information portal. They have knowledge based articles published for their customers and their own staff is also using those articles as reference.
In my opinion, there should be 2 versions- one is the public version and one is for internal reference. There are aspects like detailed explanation, escalation processes that is simply not convenient to reveal to the entire world (especially the competitor).
4. Save time and increase staff productivity
In both my previous companies, their intranets were real lousy because no one updated it. When we require information, we have to flip through our training files, search emails or in desperation make calls to our supervisors or team leaders for answers. Most of the time the customer is on the line and it’s simply so stressful. We got complaints for putting customers on long hold while trying to browse through email or trying to look for someone.
With an intranet, the information is available at just a few clicks away. It really save a lot of time.
5. Save cost and the environment (less printing using paper)
You need not be printing or keeping obsolete handouts. I used to cringe when I see the frequent delivery of A4 paper. I had no idea how many trees needed to be cut down to meet the orders requirements for my company alone.
After we had a well updated intranet, our company was able to save enormously on paper.
6. It is hard to search for information via files or archive emails
It is not practical to document and update all process in email folders. When there is new version or updated process, it is so tough to go through one by one. How about new staff who joined who never got the access? They would be really struggling.
The following are some suggestion of useful information to be contained in the intranet:

1. Company profile, ie its board of directors and management
2. Company’s location
3. Process and procedures
4. Scripting to handle various customer service scenarios
5. Possibly elearning if your employees are required to know some industrial guidelines
6. Internal social interaction page to keep the page sticky.