The common phone is a sub-$100 Nokia or nothing at all?
Even in the US there's something like 10% of people with no cell phone at all, and 50% with "smartphones" which is a very broad spectrum ranging from crap to significant household purchases before considering "data plans" are optional and also range from crap to good.
Even non-phone connection quality can be terrible - I rarely find myself on public or hotel wifi with actually good connections. The difference between 200kb of JavaScript and 10kb can often be measured in seconds.
Even in the US there's something like 10% of people with no cell phone at all, and 50% with "smartphones" which is a very broad spectrum ranging from crap to significant household purchases before considering "data plans" are optional and also range from crap to good.
Even non-phone connection quality can be terrible - I rarely find myself on public or hotel wifi with actually good connections. The difference between 200kb of JavaScript and 10kb can often be measured in seconds.