Idea aired here: http://chatlogs.metabrainz.org/brainzbot/metabrainz/msg/3351594/

A staticbrainz.org could additionally easily be placed behind a CDN to take some load off the main server (if only an ever so slight load) and might help make sites feel slightly more responsive for people browsing multiple of them, as they won't have to download the same icon/logo and other static files over and over for each domain, but can pull it out of the browser cache.

It's not a huge performance benefit, but it might help some. I don't know. The idea is properly recording in the ticket system now anyway. (Also not sure if there or OTHER would be the best place, but I reckon it can always get moved around.)