From Web Performance in Action by Jeremy Wagner.

Take 40% off Web Performance in Action. Just enter code anwagner into the discount code box at checkout at

Web Performance in Action is your companion guide to making websites faster. You’ll learn techniques that speed the delivery of your site’s assets to the user, increase rendering speed, decrease the overall footprint of your site, as well as how to build a workflow that automates common optimization techniques. This animation shows how data can pile up fast over subsequent requests.