[dragonwriter]

There are 7 billion people in the world, so your numbers suggest that about half the people in the world neither have nor do not have access to modern banking facilities.

Additionally, those with the least access to modern banking facilities probably don't have the best access to facilities for efficiently making use of bitcoins, either.

[iopq]

Some people have their spouse do the banking. Some of those 7 billion people are 3 years old.