If you prefetch the HTML of the page, the browser will have it in its local cache, so clicking the link will be instantaneous (304 Not Modified).

Regarding the back button, you can see the mis-behavior here: 1) Go here: https://zeit.co/blog 2) Scroll all the way down to the bottom 3) Click a link 4) Click back

Expected: Page returns to exactly were you left off Actual: You are scrolled to a random blog post

My overarching question is why any type of SPA is needed for a site like zeit.co?