I plotted the “potential buyers” as the number of subs addressed by iPhone-carrying operators in the launch countries according to the time when the launches happened. I did so for the iPhone 4S in 2011 and the iPhone 5 in 2012.
Now we can address availability as the area under each of these lines. The figure for the iPhone 4S adds up to be 100 billion “subscriber-days” and for the iPhone 5 it’s 130 billion subscriber-days during Q4 2011 and Q4 2012, respectively.
That means the iPhone 5 was 30% more available than the iPhone 4S. A pretty big improvement.
Take a look at the chart below or hit the link for more analysis...