Trust me when I say this:

CDN served content takes a *CRAPLOAD* of load off your site. You serve only HTML from your site (and any AJAX calls (ie: jquery...etc)).

We we went from serving all content from our webservers, to serving static from S3/Cloudfront for all images, LARGEFILES, CSS, MP3, PDFs...etc. All I can say is *wow*.

Then your machine only has to serve the actual content, not the static files. Comparison, one of our customers chooses not to use the CDN, for fear of files being stolen. They are being charged for about 200GB per month. (our hosting is very specialized). Plus our hosting infrastructure has to go through a Web Application Firewall (WAF) for all web content served (including all images/css/pdfs/etc). Our own website, get about the same hits and we host all of our images and css and javascript on CDN... plus we also host all of our main products file on S3/Cloudfront. When we switched to using cloudfront for all that our colo traffic for our traffic dropped about 85%. We haven't bumped our 95th percentile limit in a LONG LONG time now.

Also, page load times improved considerably, because of multiple requests to multiple locations, spreading traffic around and because most of the rendered info does have to traverse the "WAF"

Plus you don't get problems like your Avatar being broken... if you get my drift.