It's not just for users on slow internet or older devices- Bustle was a good example, because as a content site, it generally has a lot of assets to load. Fast

It's not just for users on slow internet or older devices- Bustle was a good example, because as a content site, it generally has a lot of assets to load. Fastboot can get you over the hump of the initial load when you're linked to a content-heavy page on the site for the first time, and hide the download/boot of the JS app for the moment it becomes ready.