http://www.quirksmode.org/blog/archives/2010/02/the_iphone_obse.html

PPK is much more coherent when sticking to documenting data. Shock and awe is a stupid way to communicate a technical position.

There are two points in his article that bear merit:

1. Progressive enhancement is just as important, if not more so, in the mobile space as it is for desktop browsers. Sites shouldn’t break.

2. Don’t automatically assume iPhone. Take a serious look at other platforms.

The rest of it is a bunch of sound and fury, surrounded by the sort of internet machismo that cyclically paints the industry as the spiritual successor to a bad middle school.

As many people in the comments have already pointed out, sales does not equal usage.

PPK attempts to wave this off with the blithe and unsupported remark:

“Next, I’m not so sure if it’s true. Mobile browser detection is really hard. None of the reports I’ve read so far show how they detect browsers. Lots of mobile browsers have iPhone in their UA strings to work around browser detects that obsessed web developers have set up. Do all traffic market share reporters work around that problem? Most probably do, but we can’t be sure.”

What browsers have iPhone in their UA strings?

http://www.zytrax.com/tech/web/mobile_ids.html

The most important examples from his article are Nokia, Blackberry and Opera Mini. And in all three of those, “iPhone” doesn’t appear in the UA string.

So ignoring the “but-you-can’t-trust-those-completely!” red herring, most usage reports paint the iPhone as having 50-60% of global mobile traffic. This is normally followed by Android and BREW.

Globally, Symbian has about the same trafficshare as the PSP, and both are significantly lower than the “unknown” categories that most reports have.

What does this mean?

It means that if a developer is going to spend time optimizing the experience for someone, that someone should be an iPhone or Android Webkit user.

Why optimize?

Because there’s only so much you can do within the confines of the lowest-common-denominator approach to mobile web development. At some point, a developer needs to step back and think: over 60% of traffic can support a much more usable site. And while if I’m going to spend hours to improve someone’s mobile experience, it may as well be the largest and most advanced chunk.

To ignore that segment of your visitors then, is nearly as idiotic as to focus only on that segment.