01 The number
Three seconds is roughly where visitors start leaving anywhere in the world. Mainland users are more forgiving — around five — and foreign-hosted sites routinely land between twenty and fifty. That is not a slow site. That is an absent one.
Deloitte's often-cited work puts a 0.1 second improvement at a 20–40% lift in funnel conversion. We mention it not because the exact figure transfers to your business, but because the direction is not in dispute and the gap here is not measured in tenths of a second.
The causes are structural — cross-border latency, packet loss, and dependencies that behave very differently from inside the mainland — and they compound. Which of them is hurting your site is a measurement question, not a guess.
Fig. — Time to first meaningful paint from the mainland, typical foreign-hosted site.
02 What we do about it