It's no secret that Apple and Google are locked in a battle for smartphone market dominance. The shear quantity of Android devices available and their lower selling price should give a distinct market share advantage to Google. Similar to that enjoyed by Microsoft in the PC space.

New data published by Kantar Worldpanel and reported on by MacRumors shows the competition in the US market. Going back two years in time, Android has had the market advantage for all but a brief period after the launch of the iPhone 4S. Apple has recently retaken the lead after the launch of the iPhone 5.

Be sure to look at the chart on MacRumors to see what I think is the most interesting thing about the data. In the summer of 2011, a couple months prior to the launch of the iPhone 4S, Android market share peaked at around 67%, while iOS bottomed near 22% share. This summer, prior to the iPhone 5 launch, Android share peaked at around 59%, while iOS hit a low near 35%. That's a decrease of around 8% for Android and an increase of 13% for iOS.

The even market share point also increased from around 45% in 2011 to about 48% in 2012.

What's interesting is the trend and how it will project into the future. The curves for both companies are smoothing. The data would suggest a market where Android is pretty dramatically losing market share while iOS is gaining it.