1) What, if anything, is the downside here?
2) Is (Google) analytics effected by the prefetch? That is, does that get counted as a page visit if the link that triggers this prefetch is not actually clicked?
Client-side analytics like GA aren’t affected.
How? It would load the HTML just as often and not download it a second time as that would invalidate the usage
> this makes for additional load on your server.
True for users who hover over links they decide not to visit
Or am I misunderstanding something here?
I'm guessing you didn't read the linked article? It preloads after 65ms on hover, at which point it estimates a 50% chance that the user will click. Hence "loaded twice as much".
> True for users who hover over links they decide not to visit
Yes, that's the point.