Secure customer portals and intranets are often ideally suited to Drupal because
- Content tends to change often
- It's much better to provide a place for customers or employees to log instead of filling in a form for every request for proprietary information
- Drupal is exceptionally good at classifying content and setting up an environment that provides multiple browsing and searching methods.
Even if you're primary website doesn't use the Drupal platform, it's not a problem to create a Drupal-based customer portal or intranet.
