Is this just a file server on steroids?

There are a lot of reasons you will want to implement document management for your organization.

Bypass requiring one or two people having to tediously post documents on your website or intranet for everyone else.

Index all your documents for flexibly searching words and phrases within them to allow users to discover relevant content.

Reduce the time it takes to find relevant information.

Categorize your documents for easier searching and better organization.

Reorganize and rename your documents and folders any way you want without breaking any links to them.

Provide multiple links in different product and project folders that can't be broken.

Secure documents and folders for specific employees, partners, suppliers, customers, and the public to access and possibly revise and manage.

Allow partners, vendors, and customer to send you contracts, invoices, and orders via email that trigger workflows and notifications.

Create project workspaces for collaboration.

Replace inflexible FTP folders for large or secure transfers.

Let users send links to documents rather than floating them around the world through email for the NSA and Google to snap up.  Provide better security and reduce parallel edits that have to be manually remerged.

Distribute reports immediately without printing.

Scan in hardcopy documents for billing and other purposes by integrating with Conversion and Capture systems.

Better security fosters more sharing.

Know who the contributors are.

Track the history of revisions that documents undergo.

Provide secure remote access without requiring VPN.

Government industry regulation compliance.

Provide HTML view for some document formats that users couldn't otherwise access.

Encourage information consumers to become contributors.

Delete or archive your documents when they're no longer needed or could pose a legal risk to you.

"Simply put, KM is about leveraging an organization's relevant intellectual assets to improve organizational performance.  It is the principal driver of the new economy and produces the strategic competitive advantage." - Michael Stankosky