About the Company. As an ISP, you are selling a service. Therefore, if a user decides to buy a service from you, they are trusting that you are going to be there to service them. An 'About the Company' web page can contain a background, recent happenings, press releases and the like, and is going to be what your potential user will know about your company. Many ISPs are still reluctant to take on-line signups.
Customers buy emotionally.
If you make it easy for them to signup through a secure web page then they are likely to signup without looking at your competitors first, because you made it easy. There is a chance of fraud, and therefore I would suggest calling the user up the next day to confirm the signup and thank them for signing up for the service. A good technical support web page can cut your technical support costs in half. Also, a 'switch from AOL' web page is very useful in getting users to trade up to your service. ISPs have gone from having an informational web site to becoming a portal.