This forum uses a traditional CDN, which is okay. There are however new ways of saving even more bandwidth and server resources. The WebRTC data channel can be used to have your own p2p CDN even alongside the one you're currently using. That way, when two users are browsing a page that contains the same resources, one visitor serves up that content to another visitor. It's a great way to take more load off your CDN and server and is very easy to setup. There is no downside to the site or users when doing this.