If you figure a conservative 24 month average replacement cycle for smartphones, then the entire market for browsers turns over every two years. And that’s the historical view. An increasing percentage of smartphone owners now receive regular software updates that provide new browsers even faster. What matters then is how old the WebKit version in a particular firmware is and how prevalant that firmware is in the real world. As usual, distribution and market share are what matters in determining real-world compatibility, and if that’s a constantly changing secnario, the data should at least reflect how things are changing. - Terrence Wood