RackWorks' point about routing over distance is the one I'd underline, and
NiceNIC's "20 locations that are just there for the list" is a fair shot at
providers like the one I work for. So let me try to answer it honestly.
The test I'd apply to any location on a provider's list: does it have local
peering and a local egress, or is traffic backhauled somewhere else? A
"Jakarta" region whose traffic exits via Singapore is a Singapore region
with a misleading label. That's the difference between a real location and
a list entry, and it's something you can check yourself with a looking glass
and a traceroute before you buy — exactly as RackWorks said.
On the locations nobody in this thread has mentioned: Southeast Asia and
Latin America. The usual assumption is that Singapore covers Southeast Asia
and Sao Paulo covers South America. For a website, that's mostly true. For
anything interactive it falls apart faster than people expect — Singapore to
Jakarta or Manila, and Sao Paulo to Lima or Bogota, are much bigger hops
than the map suggests, because the submarine cable paths don't follow the
straight line. Sao Paulo to Lima is the one that surprises people most.
So my answer to the original question: location matters less than most
people think for static content, and more than most people think for
anything with a round trip in it — and the regions where that gap is widest
are exactly the ones that get left off these lists.
