Who's using Debian?

Name of organization: ,Actiu informatica, Girona, Spain
Organization type: commercial
Home page link: http://www.actiu.net/
"how your organization uses Debian": Various internet servers to provide
common services to customers (mail, web, files, lists, remote desktops,
calendars, monitoring, etc.), internal organization servers, customers'
LAN servers.

SORRY:
+ "why you chose Debian over the competition": Because it's APT based,
stable versions are very consistent and stable, project is community
driven, and of a good project's policy about freedom and security.