Mobile web stats - why don't they add up?

With talk of Android dominating the market, why is iOS still king for our clients?

The other day, we posted about how businesses should be looking at developing websites beyond the iPhone as Android start to dominate the operating system market. However, when we looked at our analytics and that of our clients, we noticed something a bit odd: hits by iOS devices dominated on mobile.

As you can see, for one of our clients, we are seeing over 4500 hits per month by iOS, while the other top 10 devices don't come close, even when combined.