Why do the Django docs suggest a separate server for static files?
apache, django, http, mod-wsgi
Solution
In general, it's a good idea to put static content - e.g. images, CSS and JS files - on a different server and, furthermore, on a different domain/subdomain. This allows the software that serves the static files to be highly optimized and blazingly fast (for example, nginx).
The other main benefit comes from decreases in network traffic. If you serve static content from the same domain as your dynamic Django app, then client browsers send your domain's cookies as part of their HTTP request, even for static files. This is unnecessary overhead - static files will always be static - but is required because the client can't tell the difference between static and dynamic content. If, on the other hand, the static content was being served from a different domain, then it could be configured as a "cookieless domain", thus minimizing request overhead.
Problem
From the Django on mod_wsgi page: We recommend using a separate Web server – i.e., one that’s not also running Django – for serving media. Why?