I looked into Net Apps vs Statcounter a couple of years back and found the opposite to be true. From my notes (so may be a little out of date on figures):
---------
Stats Counter: Stats are based on aggregate data collected by StatCounter on a sample exceeding 4 billion pageviews per month collected from across the StatCounter network of more than 3 million websites. Stats are updated and made available every 4 hours, however are subject to quality assurance testing and revision for 7 days from publication.
Net Applications: Accumulates data from 160 million monthly visitors to its network of hosted websites that collect statistics. The average traffic for a HitsLink customer is just over 1000 page views per day
------
On sample size Net Apps are not nearly as good nor do they have many foreign market users to give a true global picture. It was not until 2010 that Net apps weighted by country population figures which skewed their results heavily to the US market share. And it has been alleged their stats are for sale.
--------- Stats Counter: Stats are based on aggregate data collected by StatCounter on a sample exceeding 4 billion pageviews per month collected from across the StatCounter network of more than 3 million websites. Stats are updated and made available every 4 hours, however are subject to quality assurance testing and revision for 7 days from publication.
Net Applications: Accumulates data from 160 million monthly visitors to its network of hosted websites that collect statistics. The average traffic for a HitsLink customer is just over 1000 page views per day ------
On sample size Net Apps are not nearly as good nor do they have many foreign market users to give a true global picture. It was not until 2010 that Net apps weighted by country population figures which skewed their results heavily to the US market share. And it has been alleged their stats are for sale.