Hi there. The bandwidth measurement is purley from our JS bundle. We are saving roughly 32kb (47kb - 15kb) from our previous article bundle with jquery... so 32kb x 5 million (unique pageviews) = ~160gb so actually more than I stated in the article. Now we do use a CDN but the idea is that we would have the lowest js footprint possible especially b/c of things like 3rd party ads which we unfortunately can't control.