We measure internet usage trends. To accurately measure usage, we have to base our stats on page views (and not unique visitors). Let's look at an example:

Person X uses two browsers. On a particular day, they load one page in Browser A. They load 500 pages in Browser B.

If we based our stats on unique visitors then usage of Browser A and B would both be recorded as 50%. This is obviously incorrect. This does not fairly represent the usage of the browsers given that Browser B was used 500 times more than browser A.

Using page views as the basis of our stats means that Browser A will be recorded at less than 1% in our stats whereas Browser B will be recorded at over 99%. In our view, this gives a more accurate representation of actual browser usage.