Ciao.
Ho trovato in questo articolo
You do, however, need to take care of serving compressed HTML, CSS, client-side scripts, and any other type of text content. If you make XMLHttpRequests to services that return XML (or JSON, or plain text), make sure your server gzips this content as well.
sinceramente non mi era mai venuto in mente
ma non sembra una cattiva idea anzi .............

che ne pensate ?