Why host your Drupal module/theme at Drupal.org?
Many reasons!
- Larger User Base - Most users check Drupal.org first and assume the project doesn’t exist if it’s not there.
- Consistency Is Understandable - It is much easier for someone new to Drupal to understand how to download and install themes/modules from a central location rather than 3 or 4 central locations
- Unified Issue Tracker - “My Issues” will show any issues you are subscribed to for any Drupal project, instead of having to go to different sites to check
- Usage Statistics - Any project or theme on Drupal.org has tracked usage statistics via the Update Status module
- Update Notifications - A Drupal website will notify (even email if you prefer) you when a Drupal.org project is updated via the Update Status module
- Programmatic Updates & Downloads - Hosting everything at Drupal.org means that Drush, Aegir, Plugin Manager, etc. can all have a uniform method of downloading and updating projects.
- Encouraging Activity - Users are more encouraged to contribute bug reports, patches, etc., if they only have to do so in one place, with one account, and one set of skills.
- Co-contributors - It is trivial to add more CVS contributors to your Drupal.org project, and more difficult if these contributors would have to be set up in an external site
- Install Profile Integration - Drupal’s Install Profiles give you pre-packaged versions of Drupal, complete with all required modules and themes. They cannot do this if any of the modules or themes are not hosted on Drupal.org.
I also made this into a handbook page.